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  1. Trailer Brake Controller
  2. CURT
  3. Electric
  4. Electric over Hydraulic
  5. Proportional Controller
  6. Indicator Lights
Curt Spectrum Trailer Brake Controller - Dash Mounted Knob - 1 to 4 Axles - Proportional
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Curt Spectrum Trailer Brake Controller - Dash Mounted Knob - 1 to 4 Axles - Proportional

Item # C51170
Our Price: $239.95
$214.95 after $25.00 Mail-In Rebate
Trailer Brake Controller
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Shipping Weight: 0.86 lbs
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Product Expert Kathleen M

Is this right for you? Product Expert Kathleen M says:

Yes, if you:

  • Want a seamless factory look without having to drill into your dash
  • Like getting at-a-glance feedback about braking status and trailer connection
  • Have a hard time seeing indicators that are dimly lit, especially when towing during the day

No, if you:

  • Rely on the manual override to feather the brakes if someone cuts you off or to reduce sway
  • Swap trailers often - getting this controller adjusted takes a little finesse
Mount the control knob of this proportional brake controller on your dash for a from-the-factory look, and install the main unit out of sight behind the dash in any position or angle. Adhesive backing gives you the option of a drill-free install. Great Prices for the best trailer brake controller from CURT. Curt Spectrum Trailer Brake Controller - Dash Mounted Knob - 1 to 4 Axles - Proportional part number C51170 can be ordered online at or call 1-800-940-8924 for expert service.
  • All Info
  • Reviews (252)
  • Q & A (0)
  • Photos
  • Why etrailer?

CURT Trailer Brake Controller - C51170

  • Electric
  • Electric over Hydraulic
  • Proportional Controller
  • Indicator Lights
  • Up to 4 Axles
  • CURT
  • Dash-Mounted Knob
  • Hidden
  • Automatic Leveling
  • Up to 360 Degrees

Mount the control knob of this proportional brake controller on your dash for a from-the-factory look, and install the main unit out of sight behind the dash in any position or angle. Adhesive backing gives you the option of a drill-free install.


  • Brake controller activates trailer brakes in proportion to your vehicle's braking action
    • Automatically adjusts trailer's braking based on deceleration of tow vehicle
  • Dash-mounted knob keeps your vehicle interior looking sleek while giving you easy access to the brake controller
    • Lets you adjust braking output and sensitivity with the turn of a dial
    • Gives you a manual override at your fingertips
    • Offers simple diagnostics with colored LED indicators
    • Mounts to dash with included screw, or you can use the included adhesive pads for a drill-free installation
  • Main unit installs out of sight behind the dash in any position, direction, and angle
    • No more banging your knee on a bulky controller
    • No interference with airbags or other vehicle accessories
    • Custom plug-in adapter (sold separately) available for select vehicles to reduce installation time
  • Compatible with ABS brakes, cruise control, low-voltage wiring, multiplex wiring, and PWM systems
  • Assembled in the USA


  • Application: trailers with up to 4 axles (8 brake assemblies)
    • Compatible with electric or electric-over-hydraulic trailer brakes
  • Main unit dimensions: 3" long x 3-1/2" wide x 7/8" tall
  • Control knob dimensions:
    • Extension: 1-1/2"
    • Diameter: 1-3/4"
  • Cable length: 4'
  • Limited lifetime warranty

The Curt Spectrum brake controller is all about easy installation and keeping the interior of your vehicle clutter-free. With the main unit mounted out of sight behind the dash, all you need is the control knob to operate the settings on the brake controller. You won't be banging your knee on a bulky controller or ruining the sleek look of your interior.

Curt Spectrum Operation

The Spectrum's dash-mounted knob puts control of your trailer's brakes at your fingertips. In addition to giving you fast, simple power adjustment and a manual override, it has colored LED indicators to offer diagnostics and let you know what the brake controller is doing at a glance.

Curt Spectrum Dash-Mounted Knob

The Spectrum has a full menu available in the control knob so you can get your settings just right. To switch between modes, press the control button in the center of the knob. Each mode has its own distinct LED display with several different colors and patterns to eliminate any guesswork as you cycle through.

Curt Spectrum LED diagnostics

Output: Braking output is the maximum amount of power that will be applied to your trailer's brakes. How much braking output you need is determined by the weight of your trailer; a heavier trailer will need more power to bring it to a stop. You want to set the braking output as high as you can without locking up the brakes. Adjust the braking output by applying your brakes and turning the knob clockwise. Once you've set up the brake controller the first time, you shouldn't need to adjust the settings until the trailer load changes, you switch trailers, or road conditions change.

Sensitivity: This controls the aggressiveness of your trailer's braking, meaning how quickly the brakes reach the set output level. This is a great adjustment to make when you're towing a heavy load and the trailer will need more umph to bring it to a stop so it doesn't push your vehicle forward. If your vehicle takes too long to come to a stop, increase the setting. If it stops too abruptly, lower the setting. You may also need to adjust the sensitivity based on your own preferences, or when the trailer load or road conditions change.

Manual Override: The Curt Spectrum keeps the manual override within easy reach. The manual override functions as time-based for a slow reduction in trailer braking, great for stopping sway or controlling your trailer's momentum in an emergency. To engage the manual override, just press and hold the button on the control knob. This will activate the trailer's brakes and brake lights without you having to apply the brakes on your tow vehicle, perfect for limiting trailer movement while you're cruising.

Curt Spectrum review

Simple, Out-of-the-Way Installation

Unlike many proportional controllers on the market, the Curt Spectrum has almost no mounting restrictions. It comes in 2 pieces: the main unit and the control knob. Because the only part that you need to be able to access is the control knob, the main unit can be mounted out of sight and out of the way. You don't have to worry about dinging your knee on a bulky brake controller or interfering with your vehicle's lower airbags.

Curt Spectrum Dash Knob

The dash-mounted control knob can be installed in any convenient spot that's easy for you to see and reach. This can be a blank switch panel, an open spot on your center console, or wherever there's space on your dashboard. Because the knob sits flush against the dash, you don't have to worry about clearance behind the dash when you're installing it either. You can either use the included screw to mount the knob or use the adhesive pad for a drill-free installation.

Curt Spectrum Install

Once you've decided where you want to put the control knob, you'll need to find a good place to install the main unit. Your only restriction is the 4' plug-in cable that has to be able to reach between the main unit and the control knob. Thanks to the 3-axis accelerometer, the main unit can be positioned at any angle or position. No matter how you install it, the unit will sense the direction of travel and its orientation.

If your vehicle already has a plug-in brake controller wiring harness, just connect the main control module to it. Otherwise, you will need to purchase a vehicle-specific wiring harness (sold separately) to plug into. If a harness is unavailable for your vehicle, hardwiring will be necessary.

Installation Accessories

See also's exclusive 7- and 4-way brake control installation kit (ETBC7 - sold separately) if you don't already have a 7-way plug at the back of your vehicle.

Note: If a custom brake control wiring adapter is not available for your vehicle, a 30-amp circuit breaker (sold separately) may be required for installation.

Proportional Braking

What is proportional Braking

The Curt Spectrum brake controller comes equipped with proportional braking to give you the best towing experience. Proportional braking means that your trailer brakes mimic your tow vehicle's brakes. If you slam on the brakes in your vehicle, your trailer brakes will activate with the same intensity; if you brake lightly, your trailer brakes lightly too. The trailer's braking is in proportion to your vehicle's braking. This saves wear and tear on the tires and the brakes on both your vehicle and trailer.

The Spectrum uses an internal 3-axis accelerometer to sense how your vehicle is braking so it can send the right amount of braking power to your trailer. It measures the inertia of your tow vehicle and activates the trailer's brakes to ensure that your trailer slows at the same rate. The result is uniform braking across your towing setup. No push-pull action - just smooth, proportional braking every time.

51170 Curt Spectrum Trailer Brake Controller - Dash Mounted Knob - Proportional - 1 to 4 Axles

Installation Details C51170 Installation instructions

California residents: click here

Customer Satisfaction Score:

Customer Reviews

Curt Spectrum Trailer Brake Controller - Dash Mounted Knob - 1 to 4 Axles - Proportional - C51170

Average Customer Rating:  4.6 out of 5 stars   (251 Customer Reviews)

Mount the control knob of this proportional brake controller on your dash for a from-the-factory look, and install the main unit out of sight behind the dash in any position or angle. Adhesive backing gives you the option of a drill-free install.


I ordered the Curt Spectrum trailer brake controller after much research. I was looking for a brake controller with a clean looking install (I didn't want an underdash mount) for my 2020 Chevy Blazer. My Blazer had the tow package from the factory which made the install fairly easy. All the wiring for a brake controller is there behind the driver side kick panels. The Curt Spectrum once installed and adjusted works flawlessly. Just follow the enclosed instructions to adjust the Spectrum for the load you are hauling. I could not be any more pleased with the way this product works and highly recommend the Curt Spectrum brake for your auxiliary braking needs.


This is my 2nd purchase of Curt spectrum brake control. When installing the first device, I accidentally broke one of the 6 wires (wiring the plug connector to the led display knob). I tried to fix it but it didn't work for long. That's why I had to order a 2nd device. For the installation of the 2nd, I was very meticulous because the 6 wires are very fragile. I succeeded by taking my time and everything works very well. The Curt company would do well to manufacture this device more robustly. For looks, it's ok in my 2019 Honda Passport.

Ceci est mon 2e achat de Curt spectrum brake control. Lors de l'installation du premier appareil, j'ai par accident brisé un des 6 fils (wiring the plug connector to the led display knob). J'ai tenté de le réparer mais il n'a pas fonctionné longtemps. C'est pourquoi j'ai dû commander un 2e appareil. Pour la pose du 2e, j'ai été très minutieux car les 6 fils sont très fragiles. J'ai réussi en prenant mon temps et le tout fonctionne très bien. La compagnie Curt aurait intérêt à fabriquer cet appareil de façon plus robuste. Pour l'apparence ,c'est ok dans mon Honda Passport 2019.


This brake controller works perfectly for my 2014 Audi Q7! The instructions were easy to follow thereby making the installation a straightforward process. The hardest part was deciding where to install the dial. The dial has a solid and deliberate feel when turning and numerous options for fine tuning.


No modifications required. I didn’t want to drill any holes in the new truck dash. This easily mounts in the clip provided with a small cable coming from under the dash.


The brake controller was a breeze to install. Drilled a couple of holes, mounted the remote and attached the base unit. The hardest part was figuring out where the pins went in the connector,better documentation would have helped here. This is my first brake controller but the operation is fairly simple. Stops my trailer as expected. Buying the custom cable for my specific truck was well worth it. I would highly recommend this controller.

Its been a year and the controller is still working great. Biggest issue is that occasionally it will display a single odd light. A quick tap of the brake clears it. Don't know why it happens, but it does. It seems to be working fine and stopping my camper as needed. I still highly recommend it.
Jim W - 05/27/2022


Looks great and works well. Only gripe I have is that I don't use it enough to remember what all it does at the different light colors. More of an issue for me, not the product. Matches my 2020 Ford Explorer interior and other dials. Looks factory.


After knocking my knee into my brake control for the last 20 years with the new GMC Savana I wanted something a little different. Technology has moved trailer brakes forward quite a bit and Etrailer has an immense amount of information!
I original looked at the Tekonsha Prodigy RF Wireless Trailer Brake Controller but it would take up a valuable power outlet with the control unit but it's kind of trailer specific as the control mounts to the trailer you never know when you might have to tow another trailer and was leery of the control wandering around the console, Next up was the Redarc Tow-Pro Elite Trailer Brake Controller but did not like the control mounting options. Then ran across the Tuson DirecLink Lite Trailer Brake Controller crazy amounts of technology in this unit but again concerns over the remote so after lots of head scratching the Curt Spectrum seemed like the best choice. Easy install very small control box mounted easily with the included double stick tape under the dash. I moved my traction control button to the left where a blank filler was you have to cut a little piece of it off to get it into the hole as the are "keyed" to specific locations I guess but worked perfectly! I left enough slack in the connection so I can simply disconnect the harness if I am not towing for awhile as the blue indicator lights come on every time you hit the brake if its disconnected. Just installed it so I will send an update after our first trip with the new rig but I'm thinking it will work as described. Thanks again etrailer fast shipping great information!!!!

It has worked out great, I have over 4,000 miles of towing with it highly recommend it!!
Bob I - 01/13/2020


It did not work out at all for my three axle trailer. Every time the brakes were applied it would go in to over load. Did not matter what setting it was on. Would not recommend to any one.

An overload will occur when there is a back feed from somewhere usually on the blue brake wire from the tailer.
-- Etrailer Expert Sierra K - 06/22/2022


I knew I wanted to have something like this due to the look, function and size. The package was small. Installed pretty easily with minimal headaches. I just watched the videos online to see how others did it and how to steer away from making damaging mistakes. The booklet was also very helpful to make everything fit as it should while putting the steps in order.

As I pull a trailer 90% of the time, I wanted something to have the easy manipulation for the brakes yet have an aesthetically pleasing look. This does just that. Brakes on one setting. Adjustable on two other settings. Very quick.

Although I did have to play with the settings to make sure it wasn’t jerking me in my seat every time I pushed the brake pedal, after a day, smooth sailing.

I do recommend you seriously think about this brake controller. Ease of install and the application is perfect.

Wonderful! It has been a great tool!
Evan - 11/10/2020


2019 Honda Ridgeline RTL AWD—
The Curt
Spectrum C51170 controller and harness C51392 was exactly as I had read it would be! All connections hooked up as described and all connectors fit! The knob works as described but I have yet to hook up trailer to get response from the accelerometer! I’m sure the quality shown it will work fine! Only problem I had was access under the dash. Thanks Bill and etrailer! Pictures attached!

I really haven’t used it much after install except to test with empty car trailer. It worked well. Three or four people I have showed it to have been impressed! Thanks
George - 05/27/2020


Everything installed great. The overall look of the knob if excellent. The direct plug in to the Ford OEM brake plug is excellent. Have not towed anything yet.
P.S.: The screw-in base with well nut - which is the more secure option (not the adhesive option) for the knob... the screw prevents the knob from seating perfectly square... the base bottoms out just slightly on the screw. It does click in, the screw is a very flat pan head... perhaps there is a flatter screw or the there is more space in the knob undercarriage, but another 1/16" of space probably gets it just right. If the seating gets weird (i.e in cold weather may shrink cause plastic to contract slightly and lose seating, I can always use a machine screw and nut washer to clean it up... plenty of space to access the fastener from mounting place. 2008 Ford Expedition.


This controller is a really good concept but kind of challenging to get dialed in correctly for each load. When braking in a straight line it performs as expected but when braking while turning or on bumpy roads it often times surges the brakes making them lock up.

I have been using this product for 1 year and am now figuring out ways to work around the surges. Best way I've found is to keep the sensitivity on high and only adjust the power setting.

The 4 star rating on this product is for how small and sleek the adjustment knob is vs standard brake controllers installed In the dash it feels almost factory.
Install took about 5 -10 minutes

Overall I am happy with this purchace
it's just not quite as user friendly as I'd hoped.


The controller works great when hooked up to the trailer. Install looks clean and much nicer than any other controller. Very simple to use. Only flaw, and I own 2 of these in different trucks that do the same thing, is when not hooked to a trailer sometimes when you pick the brake petal, the lights on the controller stay lit up until you hit the brakes again. It has happened once where it stayed on and I got out of the truck and left it for a few weeks, not needing the truck, and ran the battery dead.

I spoke to Curt about this issue. They told me the Curt Spectrum Trailer Brake Controller light stays on. If you have a vehicle that will sit for an extended period of time, they recommend using a battery maintainer like the Duracell Battery Charger and Maintainer - AC to DC - 6V12V - 2 Amp Part # DU27FR
Duracell Battery Charger and Maintainer - AC to DC - 6V/12V - 2 Amp
-- Etrailer Expert Thomas M - 01/28/2022


I bought this because I wanted a factory look. This was easy to install and looks great. You have to learn what the different colors and settings do but it’s not that difficult. Overall I am very happy with this brake controller.

I have thousands of miles on the trailer now. The brake controller has worked flawlessly. I have towed cars, ATVs and loads of lumber just set the controller for the load and it does the rest. Excellent product.
Doug - 04/26/2021


I've had the brake controller in use
for over a year in my 2012 Nissan Frontier. The install was easy and took about an hour. My truck is a 2WD model so I mounted the controller in the plug that is used to select between 2WD and 4WD on vehicles equipped with 4WD. So the install look like factory.


The compact remote control knob feature is a good plus for this product. Installation was really easy with the interface harness on the second generation Tacoma. I haven't had a lot of towing time with it but can offer the following insight.

The control lights are easy to use and adjust. They appear to be dimmed with pulse width modulation so if your eyes are sensitive to it you might look at one before you buy. Hopefully they can go PWM-free at some point. The "white" color lamps appear as a mix of flashing red green and blue. Indicator lights are plenty bright in the daytime but the lowest dim setting is too bright. Perhaps this was done to minimize the PWM flashing at the dim setting. I had to locate the knob in the shadow of the steering wheel to keep the light out of my eyes at night.

I've also noticed a single artifact light on many occasions after brake release (see pictures). So far the lamp color has been red, green, and blue however I have not yet seen a "white" one. One of these lights often come up in random positions on the dial. This lamp will continue to burn after I get out of the truck, and won't go out until I press the brake pedal again or push the knob. If I push the knob the output or sensitivity adjustment mode arc comes up briefly and it goes out after a bit (as it's supposed to). OEM brake control harness and grounding were sound with typical resistances around a milliohm or less.

This controller is a considerable parasitic draw on the battery even with the lamps out and the ignition switch off. This could be an issue particularly if an artifact light is not noticed and the truck sits for more than a week(which mine sometimes does). A depleted battery made me look into this with a Fluke ammeter. You might consider pulling the fuse if the truck will sit or hook up a trickle charger.

I tried to make contact with the manufacturer to see if they had any free convection requirements for air flow around the main module (air cooling at 100% duty cycle), and to understand what is going on with the controller and if there was something that could be done to fix the lights, perhaps a firmware update or something but never got any replies. The folks at etrailer maintained good communication and were excellent to work with but I don't feel the manufacturer is willing to support their product. This could be an excellent product if they can address these issues.


Functions well, easy to adjust and manage. Only issue was during installation, the mounting bracket doesn't work well with the adjustment knob, had to fab a better mount that allow the control cable behind the knob to have some relief. No biggy, just frustrating I had to do that....still a clean installation.


I really like the finished look of this controller after it is installed (see before and after pictures attached)! I also like being able to finely tune it to my need using the power output and sensitivity adjustments. I do have a minor issue with connecting a trailer to my 2020 Jeep Gladiator, though. If I connect the trailer while the engine is running, the electronic stability control and engine start/stop services on the truck disable themselves. Turning the ignition all the way off an on again resolves the issue, as does having the engine off when I connect the trailer. Aside from that minor inconvenience, this controller works admirably and I would buy it for other vehicles.

Installing was simple with the adapter for factory wiring. The most difficult part was identifying the location for the knob and taking the dash apart to install it properly. The finished appearance is clean and the only visible aspect of the entire system is the control knob.

With the sensitivity and power controls on mid-level, the trailer tires were skidding on quick stops. Tuning the settings to have less sensitivity and less power quickly corrected that issue. I am quite happy with this controller!


Worked well in my Infiniti 2017 QX60 but install was not that easy.
First unlike other etrailer products, I could not find an install video for my car. For other Infiniti owners out there, the brake controller connector is located along the wiring harness connected to the OBD connector. You cannot see it as it is lightly taped up, you just need to feel for it and pull it down. Secondly it is *capped*. The cap looks very much like the plug itself so don't be confused. Remove the cap and you can install. Make sure you get the right Curt adapter for your car.
Secondly the install requires the user to insert the crimped controller wires into a connector for control module. There are videos on how to do this however it did not go as easy as shown. Maybe I had a defective part, but there is clearly only one way to insert the wires but I had to insert with significant force to get them in all the way.
Once installed the unit worked fine with my 3,800lb RV trailer. A few nits: Occasionally the control knob will leave as one of its lights on after the car is turned off. Its happens occasionally and can be reset by pushing the brakes again but seems like a bug? Also the knob will *always* light up if you press the brakes even if you do not have a trailer attached. There is no way to turn this feature off and can be kinda annoying if you do not tow that much.
Overall, works as advertised and like how it can be tucked away, but wish the install was better explained for my vehicle and didn't bother if there was no trailer attached.


Great product. Easy install in under 45 minutes to integrate into factory OEM harness. 2017 Land Ro er Discovery Sport with factory trailer tow package will be plug and play with this controller, and Curt custom wiring Adapter C51322. The factory brake controller integration harness is directly behind the OBDII connector on the driver’s side. Everything else is in place. Note: your factory OEM tow connection MUST be dealer activated in your vehicle. Without that activation, the body controller will not pass power to the brake module.

There is ample space inside the dash on the left side, behind the left knee bolster to place the control module in a securable and protected location. This requires only 3 easy to remove panels, and 2 screws to reach. If oriented properly, the DIP switches are accessible in future by removing the dash side panel (zero tools required).

There are multiple locations for the control knob. The look and style of the control knob fits perfectly with the design of the interior. Love the ability to use a drill or no-drill installation method.

We haul our Forrest River travel trailer with this vehicle and previously used a time-based controller that “fought” with the vehicle’s integrated trailer stability control and anti-sway detection. This controller has solved this issue and gives complete control while integrating seamlessly with factory stability systems.

Even with the output or sensitivity at high levels, this system still works perfectly with the vehicle trailer stability control. This was a vast improvement over our old time-based controller.

Great function and fantastic look. For a non-OEM product, this truly does have an OEM look, function and ease of installation. Curt did a great job with this.

My only nit is that both Curt and etrailer do not recognize the factory connection adapter harness as an option on the Discovery Sport. TIP: If you select the Land Rover Evoque (shares the same platform as the Discovery Sport) the options become correct for your Discovery Sport as far as factory adapter harnesses.

Super fast delivery. Would be better if drop-ship items included an actual tracking number instead of only the user login web based tracking option. The web based tracking required logging in to monitor for delivery times. Some kind of automated text or email shipping updates for drop-ship items would make a great buying experience into a fantastic one.


I chose this controller as the main module fits out of sight and does not have to be aligned or leveled. I attached it to the parking brake bracket on our Pilot. The LED rotary control knob fits nicely on the dash and after inserting the cable through a small hole in the dash, connecting the plug was simple with the pins that were attached to the cable. What was confusing was the instructions do not mention there are two base plates - one for adhesive mounting to the dash and the other for drill mounting (what I did). I tried to snap the rotary knob into the base plate I mounted, but it would not fit. I found out that the rotary knob actually comes with the adhesive mount already attached and you have to use a small screw driver to pry it off so you can use the other base plate. Luckily Curt has an installation video on their web site that showed removing the adhesive plate. I generally do not start taking apart precision gear without some hint of what should be done. Curt also has a custom cable that plugs into this unit and the port on my Pilot.

When I get our trailer I will be able to review the performance of this controller.


I'm very happy to have the ability to have (Brakes) on my trailer now since Jeep dident offer A brake controller . I just wish it was A little easier to adjust & dial in . I have somehow misplaced the pocket instructions & cant get it to adjust any better now . It would be nice if you could just turn it up & get more braking out of it ?? Not real pleased with all the sequences needed to get it to do what should be A Simple job !!!!

Thank you for your review on the Curt Spectrum brake controller. You should be able to adjust the braking power by turning the knob clock wise. The LED lights will go from green to red. Is the brake controller not allowing you to adjust the braking power? I am happy to assist.
-- Etrailer Expert Heather A - 12/17/2021


I installed it in a Jeep Gladiator. Easy install (the Gladiator is pre-wired so I just needed a harness). No problems at all!


Had it out on a 3000 mile trip this summer and it worked great. never felt any pulling or pushing on the toll vehicle no wear on the brakes. really happy with this device.

Great its nice not having to set the braking its all automatic.
Henry A - 10/26/2022


Honda Ridgeline 2019 Install
Plan to
tow an RPOD 195 Travel Trailer as soon as I pick it up
Simple Installation
Didn't need to remove dash to install, as free space behind this location.
Knob on lower left of Dash.
Module Tie Wrapped to the Parking Brake Bracket under the Dash.
Used the C51392 Wiring adapter to connect the Brake Controller to the Truck.

Pictures of Dash Install only.
Haven't functionally tested yet as I am waiting on Delivery of the Trailer.

Show More Reviews

See what our Experts say about this CURT Trailer Brake Controller

  • Is There a Way To Turn the Light Off On the Curt Spectrum While Not Towing
    The Curt Spectrum Trailer Brake Controller part # C51170 will illuminate even without a trailer connected that is correct. If you don't wish to see this light each time you hitch the brakes without a trailer attached then you will either need to mount the control knob in a location that is still within reach but not in direct eyesight or you can unplug the harness that connects the control knob to the control box. I cannot recommend you splice into any of the wires to make your own sort...
    view full answer...
  • What is Needed to Change Factory Curt Brake Controller to Curt Spectrum on Renegade Valencia s2vr
    If you already have a Curt brand brake controller, then the good news is all you will need to install the Curt Spectrum Brake Controller # C51170, is the brake controller. The chassis of your motorhome really doesn't matter at this point because all you need to do is unplug your current brake controller, plug in the main module and find a suitable location for the control knob. I'm not sure what year your motorhome is, but most Valencia's have some space just to the left of the driver...
    view full answer...
  • What Colors Will Curt Spectrum Brake Controller Light Up with Brake Pedal Pressed
    The Curt Spectrum # C51170 will light up from green to red (with the trailer connected) depending on what power setting you chose. This will be the case whether you are parked or heading down the road. I confirmed this with my contact at Curt. I've also attached a photo showing what the display will look like as well as a review video you can check out.
    view full answer...
    Image 1 for Image 2 for Image 3 for
  • Curt Spectrum Lights On Overnight in my Chevrolet
    Good news is nothing is wrong with your system. I reached out to Curt and they have ran into this a few times with the newer model Chevrolet pickups. Basically the truck occasionally will run a systems check. This is a quick surge of power that gets sent around to verify everything. The Spectrum picks up that signal and gets confused when you open and close the door it is basically resetting it for lack of a better term. The LEDs that you see are just that lights similar to a phone...
    view full answer...
  • Troubleshooting Installation of Curt Spectrum Brake Controller on 2011 Toyota Sienna
    The calibration process of the Curt Spectrum # C51170 should only happen after initial installation and should be run before you plug in the trailer to your tow vehicle. You should have seen the green lights on the knob light up in a clockwise motion 7 times, which indicates the calibration is occurring. If you've gone through this process and the error occurred, then the lights on the knob can tell you a bit about what's potentially going on. If you're seeing all red lights that would...
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  • Is the Curt Spectrum Brake Controller Supposed to Light Up When the Vehicle is Started
    I called Curt to confirm if this is expected. They assured me that this is normal. It lights up when the vehicle is started to indicate the Spectrum Trailer Brake Controller, part # C51170, is on and looking for a connection. Once it's found that there is no connection, it will stop lighting up until a connection is made. I've linked to a video review of this controller for your reference.
    view full answer...
  • Dimension of Bracket for Curt Spectrum Trailer Brake Controller
    I went out to our warehouse to measure the bracket for the Curt Spectrum Trailer Brake Controller # C51170 that you referenced and found that it has an outside diameter of just under 2 inches (1-15/16 inches to be exact). I have attached the image you sent with this dimension labeled that you can also use for reference.
    view full answer...
    Image 1 for
  • Where to Access Brake Signal for Curt Spectrum Brake Controller in 2010 Mercedes-Benz ML350 BlueTec
    To correct the unwanted braking action from your Curt Spectrum # C51170 caused by the 3.6V monitoring signal generated by your 2010 Mercedes-Benz ML350 BlueTec you'll need to access the brake light signal at a location other than at the brake light switch. You can tap into the circuit at the CHMSL (center high-mount stop light) or at one of the two main brake lights and run that wire back to the controller's RED input trigger wire. My contact at Curt confirmed this and that you do not...
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  • Can The Curt Spectrum Trailer Brake Controller C51170 Be Disabled When Backing Up Trailer?
    The Curt Spectrum Trailer Brake Controller - 1 to 4 Axles - Proportional - Dash Mount # C51170 will only apply the brakes to your trailer when you press and hold the knob to engage the manual override, or apply the brakes to your tow vehicle. As long as you are not applying the brakes you will have no issues backing up. I included a video of the # C51170 for you to take a look at.
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  • How To Use Curt Spectrum Trailer Brake Controller C51170 With Electric Over Hydraulic Brakes
    I reached out to my contact at Curt and there is actually no specific mode the Curt Spectrum Trailer Brake Controller # C51170 you were looking at needs to be in to work with electric over hydraulic brakes. You will just hook up the trailer and adjust the settings the same as you would for a trailer with standard electric brakes, making sure you get the output and sensitivity right for that trailer. I included a video of the # C51170 for you to take a look at.
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  • Battery Drain with Curt C51170 Spectrum Brake Controller
    I'd be interested in why they think the Curt # C51170 Spectrum brake controller caused the problem. Brake controllers are directly connected to the vehicle battery, so the controller will always be receiving a very minimal amount of power. Once the vehicle is shut off, and the controller doesn't sense any vehicle motion for 10-15 minutes the controller goes into a 'sleep' mode. During this sleep mode, the vehicle would need to be left unattended for 3-4 months before the battery would...
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  • Do the Lights Flash on the Curt Spectrum Trailer Brake Controller with Trailer Unconnected
    The two blue lights (see photo) on each side of the Curt Spectrum Trailer Brake Controller part # C51170 will only display when a trailer is disconnected and the brake pedal is applied. You cannot turn this feature off but you can dim it with the included dimmer feature. You can also mount the knob out of direct eyesight which is more or less what it is designed for. If you can tell me what vehicle you will be installing the Spectrum brake controller on, I would be glad to check if there...
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  • Troubleshooting Curt Spectrum Where Green Light on Knob Is Always On
    Usually when the knob on the Curt Spectrum # C51170 only shows green lights, it means that the red wire is connected to ground side of stoplight switch or is shorted to ground; you'll want to check the wiring to make sure that your connection to the stoplight switch is correct and that it is properly grounded. You also may need to change the switch setting, which I've attached the instructions for to this answer. If neither of these address your issue, please let me know and I can give...
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  • Is There a Setting to Use Curt Spectrum Brake Controller with EOH Brakes
    The Curt Spectrum Trailer Brake Controller part # C51170 is compatible with electric-over-hydraulic trailer brakes, there is no setting that needs to be applied for this to work. It will automatically sense the type of brakes used and make the necessary adjustments needed to ensure compatibility.
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  • Curt Spectrum Trailer Brake Controller Single Red LED Light When Braking
    It sounds like your Curt Spectrum Trailer Brake Controller # C51170 is working properly. You are not getting an error code, but the number of red lights should increase as more brake power is asserted. The actual number of red lights that appear depends on how you have tuned the controller and it may depend on the inertia as well because it is a proportional controller. If you need more braking pressure then simply adjust the setting. I've attached the installation instructions to assist...
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  • Flashing Red and Yellow Lights of Curt Spectrum Brake Controller
    The flashing red and yellow lights of the Curt Spectrum Trailer Brake Controller # C51170 means you have a short on the blue brake wire. Since you just installed the controller and your 7-way that means it is almost certainly on the trailer side. This is virtually always due to a damaged, frayed, or exposed wire to the trailer brakes so you will need to trace the wires to the brakes and find the one that is injured. I have also added a link below to a help article on brake controller...
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  • Does Brake Controller Lighting Up When Driving Drain Vehicle Battery
    When you are driving the alternator of your vehicle is supplying more than enough amperage to the battery to keep it topped off. The stereo and headlights of your truck are drawing way more amperage than your Curt Triflex # C51170 so there would be nothing to worry about. You might still take some sandpaper to the pins of your trailer wiring to make sure they contacts are all clean. Sometimes corrosion on trailer wiring can confuse a brake controller into thinking a trailer is connected.
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  • Will The Curt Spectrum Flash Blue When Brakes Are Pressed With No Trailer Attached.
    The Curt Spectrum Trailer Brake Controller - 1 to 4 Axles - Proportional - Dash Mount # c51170 will flash blue on its control knob when the brakes are applied with no trailer or when it senses the trailer has been disconnected. If you look at the video I linked you can see at the 2:10 mark he will put his foot on the brake pedal and the control knob will flash blue when he does. I will also link a photo showing the meanings of all the LEDs and what they mean. It talks about the blue LEDs...
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  • Is There A Fuse To Power Trailer Brake Controller Port In 2021 Ford E-450 Cutaway Chassis?
    Since the trailer brake port on your 2021 Jayco built on the Ford E-450 Cutaway does not have any power, causing your Curt Spectrum Trailer Brake Controller # C51170 to not work I recommend double checking that fuse 41 is installed. It is a 30 amp fuse that powers the trailer brake controller, and is located in the engine compartment fuse box. Since your motorhome did not come with a factory integrated controller it is possible the fuse was left out. I included a video of the # C51170...
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  • Does Curt Spectrum have Manual Override Feature
    The Curt Spectrum # C51170 does have a manual override that maybe you weren't familiar with. If you press and hold the knob the manual override feature is active. When you press the button the brakes will begin to apply similar to a time delayed brake controller and the braking power will ramp up.
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  • Dimensions of Components in Curt Spectrum Trailer Brake Controller C51170
    On the Curt Spectrum Trailer Brake Controller # C51170 the round base of the rotary knob component measures 1-3/4-inches in diameter and has a depth of 1-1/2-inches. The main control box component measures 3 x 3-1/2-inches overall and has mounting holes spaced apart on center at 3/4 x 2-3/4-inches. I made a photo with these dimensions which is linked for you. The Spectrum does have a 10-LED display but the controller output is not limited to only 10 specific power and boost settings.
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  • Trailer Disconnected Indictor When Trailer Is Disconnected From Curt Spectrum Brake Controller
    I will be happy to assist you with the issue you are having with the Curt Spectrum Trailer Brake Controller # C51170. I reached out to my contact at Curt and they indicated that the disconnected light only comes on when you hit the brakes with your trailer disconnected. Curt advised that there is no way to disable this feature without disconnecting the entire unit.
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  • Curt Spectrum Trailer Brake Controller Initial Set Up
    The Curt Spectrum Trailer Brake Controller # C51170 is a proportional controller that uses an inertia sensor to adjust braking voltage that is sent to the trailer brakes. It has no way of reading the amount that you push on the brake pedal when the vehicle is not moving and will only send a little amount of power since it feels that there is no braking inertia. This prevents the trailer from pulling the vehicle to a hard stop when at very low speeds. As you begin to drive with the trailer...
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  • Does the Curt Spectrum Trailer Brake Controller Draw Power While Not In Use
    The Curt Spectrum Trailer Brake Controller part # C51170 only draws a small amount of power while not in use. It would only be able to kill the battery from this draw after several months of inactivity. The reason it still draws power while not in use is to store any save settings. Therefore, if you were to install some sort of in-line switch to cut power you would have to go through the setup procedure each time power is restored.
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