Brake Controller

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Curt

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Time Delayed Controller

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Electric

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Up to 4 Axles

/

Dash Mount

Curt Discovery Trailer Brake Controller - 1 to 4 Axles - Time Delayed

Curt Discovery Trailer Brake Controller - 1 to 4 Axles - Time Delayed

Item # C51120

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Brake Controller

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C51120 - Up to 4 Axles Curt Brake Controller
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Customer Photos

Electronic controller activates electric trailer brakes with a preset intensity when you apply the brakes in your vehicle. Power output and braking aggressiveness are easily adjustable. Includes easy-to-read digital display and manual override. Call 800-298-8924 to order Curt brake controller part number C51120 or order online at etrailer.com. Free expert support on all Curt products. Guaranteed Lowest Price and Fastest Shipping for Curt Discovery Trailer Brake Controller - 1 to 4 Axles - Time Delayed. Brake Controller reviews from real customers.
  • All Info
  • Reviews (209)
  • Q & A (105)
  • Videos (6)
  • Photos
  • Why etrailer?

Curt Brake Controller - C51120

  • Curt
  • Time Delayed Controller
  • Electric
  • Up to 4 Axles
  • Dash Mount
  • Automatic Leveling
  • 360 Degrees
  • Under-Dash Box

Electronic controller activates electric trailer brakes with a preset intensity when you apply the brakes in your vehicle. Power output and braking aggressiveness are easily adjustable. Includes easy-to-read digital display and manual override.


Features:

  • Brake controller activates trailer brakes with preset intensity
    • Signal is sent to trailer brakes when tow vehicle's brakes are activated
  • Adjustable, thumbwheel power output control lets you determine the amount of braking force
    • Set to maximum when you travel through hilly terrain with a fully loaded trailer
    • Back off the power output when you tow a lightweight trailer
  • Sync setting lets you adjust the aggressiveness with which the brakes are activated
    • Get full power output faster by moving slide-bar switch forward to increase activation speed
    • Achieve smoother braking by moving switch in opposite direction to supply power gradually
  • Easy-to-read digital display communicates brake force output, sync setting, and error codes
  • Self-diagnostics function monitors trailer connection and checks for shorts
  • Built-in, slide-bar manual override
  • Quick and easy installation
    • No need to mount level like proportional brake controllers
    • Mounting bracket and hardware included
    • Plug-in, vehicle-specific brake control adapter (sold separately) can be used for certain applications to reduce installation time


Specs:

  • Application: trailers with up to 4 axles (8 brake assemblies)
    • Designed for use with electric brakes only
  • Limited lifetime warranty


Time-Delayed Braking

The Discovery applies your trailer's brakes when the brake pedal in your tow vehicle is engaged. Every time you apply the brakes in your vehicle, a signal is sent - via the brake switch - to the Discovery. The controller then sends power out to your trailer brakes to activate them with an intensity set by you, at a rate determined by you. Both the amount of braking power (output) and rate of application (sync) can be adjusted to suit your preference, the road conditions, type of trailer, and size of the load. To determine which levels are best for your application, you must test out your towing setup and choose what feels best.


A time-delay controller is so named because there is a delay between the time that you initially apply the brakes in your tow vehicle and the time that the controller reaches maximum power output. Unlike a proportional brake controller, which activates your trailer's brakes based on the deceleration of your tow vehicle, the Discovery sends power out in the same way, with the same gradual delay, no matter the braking situation. Although this delay always exists, it can be adjusted by changing the sync setting.


Built-In Controls for Adjustable Power

Curt Discovery Controls and Components

The above diagram shows the controls and components of the Curt Discovery trailer brake controller.

  1. Digital display
  2. Power output control
  3. Sync control
  4. Slide-bar manual override

Output Control

During the initial setup process, use the thumbwheel control on top of the Discovery to adjust the output. The output control lets you set the maximum amount of power that will be applied to your trailer's brakes. Typically, the output is only readjusted when you experience changing road conditions or if you switch over from a heavy, loaded trailer to a much lighter, empty trailer, or vice versa. To get more power to your brakes, rotate the switch to the right. To decrease the power output, move it to the left. The output setting will appear on the digital display when you press the brake pedal or activate the manual override. This setting ranges from 0 to 10, with 10 indicating maximum output.


Sync Setting

To adjust the aggressiveness of your trailer's braking action, use the slide-bar control on the side of the Discovery to change the sync setting. If you want to reach maximum power output faster, move the switch forward. To get smoother braking action, slide the switch backward, thus supplying power to the trailer brakes more gradually. You can alter the sync setting to suit your driving preferences or to improve handling based on changing road conditions or varied trailer loads. The digital display will only show the sync setting as you adjust it.


Quick, Simple Installation

Because inertia plays no role in the functioning of this controller, you do not have to mount the unit at any particular angle. As a result, mounting options are limitless, so long as you can still easily access the controller.


Installation of the Discovery requires that you either purchase a custom wiring adapter designed to plug into the controller or that you hardwire the controller directly into your vehicle. To hardwire the Discovery, you must remove the plug at the end of the integrated wiring harness.


Installation Accessories

For easier installation, a vehicle-specific wiring adapter (sold separately) is available for most newer trucks and SUVs. One end of the custom adapter plugs into your vehicle, and the other end plugs into the controller - no hardwiring required.


Note: If a custom brake control wiring adapter is not available for your vehicle, one of the following will be required:

20-Amp circuit breaker (9506P - sold separately) for 2- to 4-brake applications

30-Amp circuit breaker (38630 - sold separately) for 6- to 8-brake applications


See also etrailer.com'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.



51120 Curt Discovery Time Delay Trailer Brake Control



C51120 Installation InstructionsInstallation Details C51120 Installation instructions


California residents: click here


Video of Curt Discovery Trailer Brake Controller - 1 to 4 Axles - Time Delayed


Videos are provided as a guide only. Refer to manufacturer installation instructions and specs for complete information.




Video Transcript for Curt Brake Controller - Time Delayed Controller - C51120 Review

Today we're going to take a look at the Curt Discovery Trailer Brake Controller number C51120. This time delayed brake controller activates trailer brakes with a preset intensity. The signal is sent to the trailer brakes when the tow vehicle's brakes are activated.It has an adjustable thumb wheel power output that allows you to determine the amount of breaking force you would set to the maximum when you travel through a more hilly terrain with a fully loaded trailer and you would back off the power output when you're towing a smaller more lightweight trailer.It also features a sink switch here on the side. It allows you to adjust the aggressiveness of the brakes. If you want it full power in this position right here. It will increase the activation speed of the brakes and you would move it back in the opposite direction to achieve a smoother braking by supplying the power more gradually.

It has an easy to read digital display that communicates brake force output, sink setting and air codes and we'll attach this to a power supply in just a moment so you can see that a little better. Self-diagnostics function monitors the trailer connection and checks for shorts. It has a built in slide bar emergency manual override and again we'll discuss that more in just a moment. It has also has a quick and easy installation. It comes with the mounting bracket right here.

The screws to attach the bracket to the controller as well as a quick reference card if you have any questions. One of the differences between the time delay brake controller and a proportional brake controller is there's no need to mount this one level the way you would a proportional controller.You can mount it up, down, side to side, as long as you can see the digital display you're good to go. This application is for trailers up to four axles or eight brake assemblies. It's designed for use with electric brakes only and it does have a limited lifetime warranty. Now we're going to attach it to our power supply and the wiring harness that we're using here is the Curt Universal Wiring Adapter for Curt Trailer Brake Controllers, number C51515.

This particular harness ends in a pigtail and it is intended for vehicles who do not come with a factory installed brake controller port. Now when you hit the brake you will be able to see the digital display and say right here we'll use our output knob here. You can go from zero to ten and we'll set that at five for right now and over here our sink all the way to nine and then slide it back to zero. We will put that at five as well. When we talk about our emergency manual override say youre in traffic and somebody cuts you off and you have to hit the brakes really quick what you would do is hitch your emergency manual override and instead of the normal amount of time it would take for the trailer brakes to brake this removes the time delay function and the maximum output that you had preset it goes to the brakes immediately to help slow you down to prevent any accidents.

That should just about do it for our Curt Discovery Trailer Brake Controller number C51120.


Customer Reviews

Curt Discovery Trailer Brake Controller - 1 to 4 Axles - Time Delayed - C51120

Average Customer Rating:  4.8 out of 5 stars   (209 Customer Reviews)

Electronic controller activates electric trailer brakes with a preset intensity when you apply the brakes in your vehicle. Power output and braking aggressiveness are easily adjustable. Includes easy-to-read digital display and manual override.

- C51120
by:

Had the controler installed in just a few minutes. 634445



- C51120
by:

Product worked as advertised. 2012 F150 already has the terminal. All adjustments work as they should with the trailer brakes. 606348



- C51120
by:

When i needed to replace my electric brake controller on my truck for pulling my trailers I first ordered from another dealer and when i got the unit and read the instructions there were about 3 items that i wasn't told about and sent it back ,so i kept searching for the controllers and came across e trailers , there were so many questions i had from my researching that when i called e trailers and talked with Preston he was so helpful in explaining the differances with controllers and i explained what i wanted and why he helped set me up with the right one .I then ordered the unit it was received faster than i expectided , it took me about 20 minutes to install the wiring harness and controller, I'm very happy with the customer service rep. Preston with help and time to explain and the choice i made thanks Preston and E trailers 584058



- C51120
by:

Purchased this controller for limited use. Really like the vehicle specific plug adaptor that came with it. Makes for a quick clean install. Clean compact design and easy to use. 544267



- C51120
by:

I bought a new car dolly with electric brakes to pull with our motorhome ( Fleetwood FlAIR 2001 ) as all states require brakes on trailers at all different weight levels. I called E trailer and spoke with Danna and after talking with her about different models I choose the C51120 time delay control, as it can be adjusted to work well with the tow vehicle . I received the control with in 3 days of the order and went to put it in and found under the dash wire a harness by Fleetwood which told where each wire on the controller went on the harness. I was able to hook it up sitting in the drivers seat. Completed the hook up and started to test the operation, to find I was not getting the proper readings. I talked with Tom and he said he would bench test a like control and report back to me, at 6 pm he left a message on our phone that he believed the problem was along the blue wire to the trailer on the tow vehicle . I started at the back of the, motorhome and moved forward testing for a brake signal, I found that the butt connector had pulled apart and was not getting current to the plug in at rear of coach. Hooked it back together and re taped the wires and it works like a charm. I want to thank all off you for the prompt and knowledgeable service, I would recommend E trailer to anyone who wants to deal with a great staff and company Thank you 237064


Comments

I used this controller to pull ma car dolly to AZ and back through all the mountains and it worked GREAT I am very happy with how it worked Great product

Bob R - 02/04/2017

22382

- C51120
by:

the brake controller with all the wiring plus the 7 pin plug was better than i thought . it even has great instructions and easy to read. the price was good . the 7 pin plug even has the 4 pin connector mounted in with it very glad that i bought it is everything that you need to make it work . everything about it is excellent very glad that i found it here at a good price . even fast shipping . again thanks for good product 230172


Comments

Use it for pulling camper works great even a good price fast shipping . Its been a year and still working great.

George D - 10/16/2016

21545

- C51120
by:

Ordered a brake control and an inline circuit breaker on Feb 11th and shipped the same day. I chose the least expensive shipping option (my bad). A combination of UPS/US Post Office, or so I was told after calling to find out where my shipment was. Tracking info said delivery by the 15th. When it didn't show I called etrailer and was told the post office had it and it was out for delivery...2 days later I finally received it (Feb 20th). I ordered a hitch a couple of weeks prior and received it in 2 days. A 49lb hitch vs a 1lb (maybe) package. Not etrailers fault but I can see why the post office is going broke with service like that! 117375



- C51120
by:

Not too thrilled with this one. Three main issues listed in increasing order of magnitude. 1. One of the segments on the display died shortly after installing. 2. The adjustment wheel is very crude and hard to dial in. 3. This one is the killer, if you start by manually applying the brakes using the slider, and then put your foot on the brake pedal, and then release the lever, the BRAKES GO FULL LOCK! That's a design flaw in the circuit. 501648



- C51120
by:

Less than 1 yr after installing on a 2017 F250, controller quit working right. It would surge brake to some high number like 7 (10 being max) regardless of the controller setting which would lock up trailer brakes. Next time it would only allow a setting of 2.5 or 7.5... nothing else. Next time it would do something different. Called Curt who recommended unplugging it for awhile. Worked for awhile then started acting up again. They're going to send me a replacement. Tbd if replacement will be better. 468124



- C51120
by:

After reading the reviews of this product I decided to give it a try myself, with a great price. When I received it within a week along with the plug and play 7 prong trailer hitch adapter, I realized I was missing something. The plug and play adapter for this product. It showed me it when I was buying and for what ever reason I didn't have the option to add it as well. It was very easy to install, like I said plug and play. The problem is it does not work. followed all the directions, double checked everything I just don't have a signal to the trailer from the break controller. Good luck 278660



- C51120
by:

This is by far the most pleasant buying experience I’ve ever had online. A wealth of information is provided for installation coupled with prompt delivery makes shopping for anything RV related a no brainer for me. etrailer is wonderful and have already started recommending this website to anyone I know. 614611



- C51120
by:

This Curt Discover controller works great. Super easy to install if you get the pigtail for your model truck. I especially like the fact that you can install the bracket under the dash on my new 2018 Silverado using factory screw under the dash. No drilling required. As always wonderful pricing and delivery from E-Trailer. 533806




- C51120
by:

This was my first order and I'm very pleased with the fast service. I haven't hooked it up to my truck yet but everything looks to be correct . 711328



- C51120
by:

product works as described, great price and fast shipping 711176



- C51120
by:

Once adjusted works great , easy to set up 707772



- C51120
by:

Works as advertised. Only minor issue is mounting the unit in a 09 Colorado. 700411



- C51120
by:

Ordering was easy. I paid to have next day shipping and it arrived by 10:30. That allowed me to install it the day before and met my schedule. The part couldn't have been easier to install and adjust! The online video was helpful. 699486



- C51120
by:

As always, the service was great, and the break box works great in my truck. Was easy to install. Only the best when I'm towing my big boys to my favorite trail. Thanks etrailer. 694733



- C51120
by:

great product great service 697009



- C51120
by:

Good quality product and easy to instal l. 677279



- C51120
by:

The controller I ordered arrived quickly and was everything as it was described....I could not be more pleased! 670280



- C51120
by:

Plug and play, 5 minutes to install.Worked perfectly! 667419



- C51120
by:

I found the under dash factory plug for the brake control per pictures that you provided with product. Almost too easy! Thanks for your complete support for installing products that you provide. 667382



- C51120
by:

My Curt trailer brake controller was a very easy install and hook up with the adapter harness. And the Cipa slip on towing mirrors are nice and simple. 663752



- C51120
by:

not real happy it said it was complete now that I got it I need part#51500 wire kit, that sucks 663293



- C51120
by:

Wish it had longer cabling, otherwise; So far so good! 654833



- C51120
by:

Very detailed website information made ordering easy. Product delivered as promised and would use etrailer for future needs. 649189



- C51120
by:

Easy to install and setup. 647591



- C51120
by:

The wiring kit fits perfectly. I had a small problem with the operation of the brakes on my trailer but a quick call to the great service department and my problem was quickly rectified. I will do business again. 635248



- C51120
by:

Work great easy to install would buy ag ain 633253



- C51120
by:

amazing fast shipping, thank you 617101



- C51120
by:

Great product, works as expected, very easy install, shipping right on time, no damage at all to the product. Very happy with my purchase thanks etrailer for filling my needs. 615033



- C51120
by:

Shipped and arrived in a timely manner. 605620



- C51120
by:

Easy install 605451



- C51120
by:

I'm Very pleased with the quickness of receiving the brake controller for my 2019 Tundra and can't beat the price for a quality controller and adaptor wiring kit ! 600829



- C51120
by:

Everything received promptly and as expected. Thank you! 597767



- C51120
by:

terrific product,excellent fit,seamless transaction! 594246



- C51120
by:

This is my second one. It just works and is priced right. 588142



- C51120
by:

Good product selection and high quality. Good service and follow up. Quick and secure shipping. 578797



- C51120
by:

Excellent customer service very professional. Fast and easy shipping. Very knowledgeable staff. I will be back. 575040



- C51120
by:

Worked very well 550732



- C51120
by:

Product works great just as described . Did have a little trouble installing it but otherwise no issues. 544469



- C51120
by:

The controller was easy to install. It works exactly as it should at a very good price. Costumer service is excellent. The first controller we received was broken. A quick phone call and two days later a new controller. Would definitely order from this company again. 541795



- C51120
by:

Product is what fits my truck for proper operation. Compact and easy to use. Price is right and is easy to install. 541792



- C51120
by:

Exactly what I wanted 524866



- C51120
by:

Works very well! Nice product and easy install! Very satisfied! 523370



- C51120
by:

Bought this for my father for father’s day gift. Worked great. He was glad to get it. 517633


Comments

He still loves it. Thanks

Debra - 06/05/2019

56197

- C51120
by:

Installed in about 5 min. Arrived ahead of schedule and instruction videos were great. Will buy All trailer stuff here in future. 517464



- C51120
by:

Good quality product ( electric trailer brake control) and fast delivery!! Very satisfied. Do recommend!! 517385


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Ask the Experts about this Curt Brake Controller

Do you have a question about this Brake Controller?


  • Difference Between Proportional Brake Controller and Time-Delayed Controller on 2018 Toyota Tundra
  • The difference between a proportional brake controller and a time-delayed brake controller is that a proportional controller is pretty simple. A time-delayed controller like the Curt Discovery # C51120 will apply your trailer brakes each time you press the brake pedal in your 2018 Toyota Tundra; it is called time-delayed because there is a slight delay from the time you press your Tundra's brakes to the time the controller reaches max power output. A proportional brake controller like...
    view full answer...

  • Brake Stoplamp Switch Wire Color For Brake Controller Install on 2016 Ford F150
  • You'll be looking for a purple and white wire, but if you're wanting to install a brake controller there is a plug and play option that would require no cutting or splicing. If you look at the installation video I've linked for you, you can see that the brake controller connector is located behind the dash, all you'll need is the correct wiring harness to connect the controller and the vehicle and you'll be good to go. If you're using a Curt brake controller like the # C51120, you would...
    view full answer...

  • How to Install Curt Discovery Brake Controller in 2008 Ford F-150 with 7-Way
  • The Curt Discovery brake controller part # C51120 that you referenced can easily fit your 2008 Ford F-150 with the custom install harness part # C51322. This plugs into the brake controller install port under the dash of your truck and then into the back of the controller and you're set.
    view full answer...

  • Can Trailer Brake Controller be Used on Harley Davidson Motorcycle Pulling Small Trailer
  • The Curt Spectrum Trailer Brake Controller # C51170 can be absolutely be used with your Harley pulling a small trailer for your pups (and in the process making your wife happy). Normally with a motorcycle you want to use a time-delayed controller like the Curt Discovery # C51120 but since the Spectrum's main unit can be mounted at any angle, this is one of the proportional controllers that can be used so long as you can find a good mounting point for both the main unit and the control...
    view full answer...

  • Brake Controller Installation Harness Recommendation for a 2015 Chevy Suburban
  • Yes, there is a port under the dash of your 2015 Chevy Suburban that will allow for a painless installation of a brake controller that won't require splicing. The harness to go along with the Curt Brake Controller part # C51120 that you referenced is the part # C51452. If you went with our most popular brake controller, the P2 part # 90885 you would only need the harness part # 3016. See the install video I attached.
    view full answer...

  • How to Find Out Where Cold Side of Stop Light Switch Is
  • In order to find the stop light switch in your truck you will need to use a circuit tester such as # 40376. Find the wires at the top of your brake pedal and use that circuit tester to find the wire carrying a signal only when your truck's brake pedal is engaged.
    view full answer...

  • Which is Better a Time Delayed or Proportional Brake Controller
  • Between the two controller I would go with the proportional Curt Triflex part # C51140 over the time delayed Curt Discovery part # C51120. A time delay controller is so named because there is a delay between the time that you initially apply the brakes in your tow vehicle and the time that the controller reaches maximum power output. Unlike a proportional brake controller, which activates your trailer's brakes based on the deceleration of your tow vehicle, a time-delayed controller sends...
    view full answer...

  • OL Message on Curt Discovery Trailer Brake Controller
  • There could be a few different things happening with your Curt Discovery Trailer Brake Controller part # C51120. The first thing that could be happening is that you have a short on the red stop light switch wire. In order to rule this out you will need to probe the red wire going into the back of the brake controller. There should only be power on this wire with the brake pedal depressed. If there is when it is not then you know there is either a short in this wire or the stop light switch...
    view full answer...

  • Which Brake Pedal Stoplight Switch Does Red Brake Controller Wire Connect to on 2013 Ford Escape
  • The second generation Escape (2008-2012) used a purple and white wire for the stoplight switch, but I could find no information about your 3rd generation Escape. The best way to find the correct wire is to use a circuit tester like part # 40376 and test each of the wires. The wire that only goes hot when the brake pedal is pressed (not with the headlights or turn signals) is the wire you want to tap that red brake controller wire into.
    view full answer...

  • Where to Connect the Adapter to Install a Curt Brake Controller in a 2017 Nissan Pathfinder
  • To install a Curt Brake Controller, like the Discovery # C51120, on your 2017 Nissan Pathfinder you will simply need to plug the Custom Wiring Adapter # C51382 under your dash like you mentioned. I am attaching a video where one of our install guys installed a Tekonsha Prodigy P2 # 90885 in a 2013 Pathfinder using the Tekonsha Wiring Adapter # 3050-P. If you skip to the 2:45 mark you can see where he plugs in the adapter for the Prodigy P2. Your Curt adapter will plug into the same place.
    view full answer...

  • Installing a Brake Controller in a 2009 Chevy Suburban
  • The 2009 Chevy Suburban does not have a port to plug in a brake controller which is the same as the trucks of the same year. But it does have the tow package wire bundle up under the dash, to the left of the steering column, held together with a white tag. Pull the wire bundle out to wire in a brake controller. With Curt brake controller # C51120 you will also need pigtail # C51515. Then you can make the following connections: Vehicle red/black wire to controller black wire for 12...
    view full answer...

  • Brake Controller Installation on 2011 Toyota Tundra
  • If your 2011 Tundra has the factory tow package, which includes the factory installed 7-way trailer connector on the rear bumper, it will be equipped with the tow package plug under the dash, as shown in the photo I've edited for you. Some models with the factory 4-pole (or 4-pin) trailer connector will also have the plug under the dash, you'll need to look for a white plug located above and to the left of the emergency brake pedal, above the toe kick. Occasionally, the plug will be located...
    view full answer...

  • Curt Discovery Brake Control Flashing 0.0 Troubleshooting
  • The troubleshooting guide included in the instructions for the Curt Discovery Brake Controller # C51120 that you referenced does not include this particular display issue, a flashing 0.0, among the possible display messages. My technical contact at Curt has never seen this particular message displayed on a Discovery brake controller. He suggested that either the display is malfunctioning or the controller is bad. Since your brakes are not engaging when you press the pedal with the trailer...
    view full answer...

  • Troubleshooting Curt Discovery Trailer Brake Controller # C51120 Installed in 2002 Chevrolet Tahoe
  • Thank you for your recent purchases from etrailer. I would like to suggest some additional testing before you return the Curt Discovery Trailer Brake Controller # C51120. This will help isolate the problem and confirm whether the unit is indeed defective. The code OL indicates that the controller has sensed an overload condition. Disconnect the trailer from the Tahoe. Apply your grounded tester to the pins at the 5-o-clock and 7-o-clock positions on the Tahoe 7-way, as shown on the...
    view full answer...

  • Troubleshooting Flashing 0.0 Error Message on Curt Discovery Brake Controller # C51120
  • The troubleshooting guide included in the instructions for the Curt Discovery Brake Controller # C51120 that you referenced does not include this particular display issue, a flashing 0.0, among the possible display messages. My technical contact at Curt has never seen this particular message displayed on a Discovery brake controller. He suggested that either the display is malfunctioning or the controller is bad. Since your brakes are not engaging when you press the pedal with the trailer...
    view full answer...

  • Curt Discovery Brake Controller Display Flashes with Left Turn Signal
  • It could be a wiring issue. Specifically it is likely related to the brake controller red wire. If that wire is not attached to the correct circuit it can cause some strange things to happen. The red wire needs to be connected to a brake switch wire that only has power when the brake pedal is pressed. If that same wire has power then the headlights or a turn signal are on then it is not the correct wire. I have heard that the correct brake switch wire is the white wire so use a circuit...
    view full answer...

  • Brake Controller Install in 2014 GMC Sierra
  • The install procedure will depend on if you have a 1500 or a 2500/3500 Series. If your Sierra is a 1500 model, you will need a brake controller wiring adapter harness, part # C51451. The 2500 and 3500 series would have the tow package wiring that sits above where the driver's left knee sits. If you click the video link I've provided, you can see a controller being installed in a 2014 GMC Sierra 1500. The FAQ link I provided shows how to install a controller in the 2500/3500 model. The...
    view full answer...

  • How Does Brake Controller Install in 2012 Ford F-150
  • When installing the Curt Discover part # C51120 with the harness for your 2012 Ford F-150, part # C51436 all you'd have to do is plug in the controller and harness and you'd be set if you have the factory 7-way like it sounds like you do. It's really a pretty simple install. Otherwise you'd need a 4-way to 7-way adapter like part # 37185 and you'd have to run the wire from the truck's frame rail to the adapter and you'd be set. See attached picture for more info on that.
    view full answer...

  • Troubleshooting Curt Discovery Brake Controller Issues on Ram 1500
  • The Curt Discovery Brake Controller # C51120 is a time-delay type that is intended to send out a pre-determined amount of braking power after you have applied the vehicle brakes. The other type that is often preferred is the proportional type that will actually sense the amount of braking force in the tow vehicle and send a proportional amount of braking power to the trailer, without a time delay. Based on the symptoms you described I think the issue could be with the wiring on the trailer....
    view full answer...

  • How to Access Vehicle Brake Light Signal for Trailer Brake Controller Installation
  • If your 2005 Toyota Sequoia has a factory-installed 7-way trailer connector you can install the Curt Discovery trailer brake controller # C51120 using only the mating wiring adapter part # C51362. If it does not then the installation will be hardwired. You can gain access to the vehicle brake light signal, which is what triggers the Discovery controller to generate output voltage for the trailer brakes, either by tapping into brake light wiring or by installing a fuse tap in the brake...
    view full answer...

  • How to Find and Access the Brake Light Switch Wire on a 2015 Toyota Highlander for Brake Controller
  • If you check out the video I attached you will see how we installed a brake controller in a very similar 2014 Toyota Highlander as your 2015 model. We had to remove the lower dash panel (13:00 mark of the video), to make accessing the green wire possible. The kit used for the install in the video is the part # ETBC7.
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  • Parts Needed to Install the Curt Discovery Brake Controller # C51120 on a 2013 Dodge Durango
  • The Curt Discovery Trailer Brake Controller, # C51120, and the Custom Wiring Adapter, # C51446, will work on your 2013 Dodge Durango without splicing as long as your Durango came with a factory 7-way trailer connector at the trailer hitch. The 7-way trailer connector would indicate that your truck has the factory tow package, which would include a brake controller plug under the drivers side dash. You should see a gray connector just to the left of the steering column. If your Durango...
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  • Brake Controller Wiring Adapter for a 2015 Toyota Tacoma with Factory 7-Way
  • No worries, the 5-wire harness will work just fine because the extra connection is for the illumination circuit and it's not needed. The Curt Discovery trailer brake controller # C51120 is a fit for your 2015 Toyota Tacoma and the direct fit pig tail adapter # C51362 you referenced is correct. You will simply plug the adapter # C51362 into your factory brake controller tow port and route the pigtail to the location of your choice so you can connect your brake controller # C51120....
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  • Troubleshooting a Curt Discovery part # C51120 Not Working on a 2002 Chevy Silverado 1500
  • On certain model year Chevy and GMC trucks and SUVs there are some connections that need to be made under the hood to make everything fully functional. It happens on vehicles with or without the factory tow package. I checked your order notes and you also bought the Curt Wiring adapter part # C51342. To see what under the hood connections need to be made check out the link I provided to the right that details everything you would need to install a controller like the Curt Discovery part...
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  • Troubleshooting Curt # C51120 Discovery Brake Controller Showing Flashing Decimal Point on Display
  • What you're describing sounds like it could either be an interruption in the trailer brake voltage output circuit, somewhere between the controller and the trailer brakes, or you could have a defective controller. Use a circuit tester with an incandescent bulb, like part # 40376 and use the probe to pierce the insulation of the blue output wire exiting the rear of the controller and ground the alligator clip. Apply the brake pedal. If the load provided by the tester causes the display...
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  • Recommended Trailer Hitch for Towing a Car Hauler with a 2019 Ram 1500
  • The hitch to fit your 2019 Ram 1500 is the Draw-Tite # 41913. It's custom designed to fit your truck and has plenty of capacity to tow a car on a trailer. You also need a ball mount, hitch ball, and pin and clip. I've linked our selections of each but you also may want to look at an adjustable ball mount. This way if you tow a different trailer sometime it'll be more likely to work for you. A good choice that has all three ball options is the Buyer's Products # 3371802225. You also...
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  • Curt Brake Controller Wiring Pigtail for 2013 Jeep Wrangler Unlimited
  • The correct pigtail wiring harness for installing a Curt Discovery Trailer Brake Controller # C51120 in your 2013 Jeep Wrangler Unlimited is part # C51515. The part # C51446 is for the Grand Cherokee.
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  • Curt Discovery Brake Controller Is Only Showing A Dot When Engaging Manual Override
  • The Curt Discovery Trailer Brake Controller, # C51120, should show only the decimal point dot when the controller is activated and a trailer is not connected. If it shows the dot all the time, the red wire is connected to the wrong side of the stop light switch or the wrong switch completely like the cruise control. If you have only the decimal point when the trailer is connected, the usual cause is that the brake controller does not sense the trailer brakes. This could be due to corrosion...
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  • Installing A Brake Controller in a 2008 GMC Yukon XL Without Plug and Play Adapter Harness
  • On your 2008 GMC Yukon XL, there is not a direct plug and play harness for a brake controller. This is because no plug is present under the dash, however the needed wires are already run so it is a simple install. You will connect the brake controller wiring with the vehicle wiring already present under the dash with butt connectors like # 05731-5. The Curt Discovery Timed Delay Brake Controller # C51120 gives you the option to either cut the connector off the brake controller or...
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  • Troubleshooting Brake Controller that Flashes When Connected to Trailer
  • It sounds like the problem is corrosion on the trailer 7-way brake output circuit which is causing the controller to only show an intermittent connection. Try cleaning off this pin on the 7-way with some fine grit sandpaper. Testing the brake controller is fairly easy. Sever the blue brake output wire near the brake controller leaving enough room to reconnect it and then apply the manual slide. Using a circuit tester like part # PTW2993, you should get output to the controller side of...
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Info for this part was:

Edited by:
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Expert Research:
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Expert Research:
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Michael H
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Jameson C
Expert Research:
John H
Expert Research:
Adam R
Expert Research:
Jeffrey L
Written by:
Lindsey S
Video Edited:
Joshua S
Video Edited:
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Video Edited:
Dustin K
Test Fit:
Nicholas E
Test Fit:
Shane T
Test Fit:
Randy B
Updated by:
Adele M
Updated by:
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Updated by:
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