Brake Controller Installation: Starting from Scratch

Custom Fit Brake Controller

Before Installation You Will Need:

  1. Brake Controller
  2. 7-Way Installation Kit (#ETBC7)
  3. 4-Pole Trailer Connector (if not already installed)




Information About 7-Way and 6-Way Installation Kits


The 7-way Trailer Connector Has a Total of Seven Wires:


The Colors of the Remaining Four Wires:





The ETBC7 and ETBC6 Installation Kits:

All the parts necessary to connect a brake controller to your vehicle are included


The 7-way installation kit pictured with all included parts

The 7-Way Installation Kit Parts

  1. 7-way trailer connector, which includes a 4-pole adapter
  2. The mounting bracket secures to the vehicle's bumper or other appropriate mounting location and harbors the trailer connector.
    • Mounting hardware, such as self-tapping screws, is included to mount the bracket to the vehicle and the trailer connector to the bracket.
  3. The gray duplex cable houses two wires that will become the 12 volt hot lead and brake wire.
    • The duplex cable runs from the trailer connector to the front of the vehicle.
  4. The black loom is a hard plastic tube that covers the 12 volt hot lead and brake wire connections at the trailer connector, protecting the connections and giving your installation a professional appearance.
  5. Circuit breakers act as midway connections for the 12 volt hot lead and the brake controller power supply (introduced later) before they reach the vehicle's battery.
  6. Butt connectors help to make connections between wires.
  7. Ring terminals attach to the end of wires and hook around battery posts and circuit breakers.
  8. Zip ties help to bind loose wires together and prevent them from interfering with vehicle components such as brake and gas pedals.




Brake Controller Installations Steps


The duplex cable has been run towards the firewall at the front of the vehicle.

Installing and Wiring the 7-Way Trailer Connector

  1. Find a suitable location to mount the 7-way connector.
    • A typical location is on the bottom of the bumper.
    • Using the self-tapping screws, secure the mounting bracket into the bumper and the trailer connector into the bracket.
  2. Plug the 4-pole adapter coming out of the 7-way connector into the vehicle's 4-pole trailer connector.
  3. Ground the 7-way connector by screwing the white wire into the frame of the vehicle.
  4. Make a small cut in the rubber sheath of the duplex cable and slightly separate the two wires inside.
    • Use a butt connector to connect the black wire in the duplex cable to the 12 volt hot lead (black wire on the 7-way connector).
    • Then do the same for the white wire in the duplex cable and the brake wire (blue wire on the 7-way connector).
    • Next, route the duplex cable under the vehicle all the way up to the engine compartment under the hood, being careful to avoid hot areas or those that may pinch the cable.
    • Before you proceed further, the brake controller needs to be mounted.
      • We will return to the duplex cable shortly.


Brake controller sitting flush on the lower right side of the dash

Mounting the Brake Controller

  1. Choose an appropriate mounting location for the brake controller mounting bracket.
    • A typical location is the lower right side of the dash, which allows easy access to the brake controller in the event of an emergency braking situation.
  2. Using the screws provided, install the mounting bracket into the dash.
    • Make sure you avoid drilling through components on the other side of the dash.
  3. Secure the brake controller into the mounting bracket.
  4. The four wires on the brake controller will be connected shortly.




The 12 volt hot lead and trailer feed have been separated before running through the firewall.

Wiring the 7-Way Trailer Connector and Brake Controller

1. Return to the duplex cable under the hood, where the brake wire (now white) needs to be separated from the 12 volt hot lead (black).



Circuit breakers mounted in the engine compartment

2. Using a butt connector, connect the blue wire coming out of the brake controller to the brake wire (white wire of the duplex cable) that was routed through the firewall.


3. Find a safe location under the hood or on the firewall to mount two circuit breakers: one 20-amp (or 30-amp; see brake controller instructions) and one 40-amp.


4. The black wire coming out of the brake controller is the brake controller power supply.


View of wires attached to positive and negative posts on battery

Brake switch wires located above the brake pedal

5. The white wire coming out of the brake controller is the ground wire.


6. Inside the cab, we only have one connection remaining.


7. With the brake controller mounted and connected, zip tie any loose, excess wires underneath the dash and under the vehicle.





brake control wiring diagram




Questions and Comments about this Article

John

I have a 09 GMC Sierra 1500 on the brake controls wires on the truck side we have blue, red/black. ,green , yellow on the controller it Blue, black , white and red help

Etrailer Expert
Reply from Victoria B.

Those are non-standard wire colors for the GM factory brake controller wiring harness. The bundle typically includes 4 or 5 wires: red/back, white, light blue, dark blue, and possibly an orange wire. I have linked a help article with more info. If you are sure that you have the right wire bundle, the best option is to use a circuit tester to determine which wire has which function. The brake controller wires will be wired black to 12V power, white to ground, blue to brake output, and red to stop light signal.

Bob R.

Wouldn’t the controller be on all the time wired up this way? Shouldn’t there be relay to supply key on 12v?

Etrailer Expert
Reply from Victoria B.

Most controllers have a sleep mode that they enter into after about 15min of non-use. They pull minimal power in sleep mode, but will maintain any settings for different trailers - if the controller has that ability. If your controller has these settings features and something is added to the system to essentially key the controller to the ignition, then these settings would not be maintained when the vehicle is not on.

Jeff W.

Is there a difference if i use the bolt on circuit breakers as opposed to the in line blade stlye? I have an in line and i feel it may be tripping after initial brake application. Touareg towing a 23.5 foot travel trailer. Thoughts?

Etrailer Expert
Reply from Jon G.

As long as it's rated appropriately for your application then you can really use any type of circuit breaker. I will say that if your current circuit breaker keeps tripping when you hit the brakes then that leads me to believe that the circuit breaker is bad or you have some bad wiring (or connection) somewhere. Unless it's the circuit breaker, a new circuit breaker won't solve anything.

Reply from Jeff W.

@JonG Thanks, the brakes work but sometimes feel like they ease off after initial application in light braking situations. I will adjust and play around with the controller when i pull out tomorrow. Too much makes it lock at low speeds so i backed it off, i have now warped my second set of front rotors! Go figure!

Leonard Y.

I just get a red dot when I step on the brakes, no trailer brakes

Etrailer Expert
Reply from Jon G.

What controller do you have, and have you tested while you are moving or just when you are parked? If it's a proportional controller then it won't send power if you are sitting still.

Todd

So will the trailer brakes work without a hot wire running to 7way plug??

Etrailer Expert
Reply from Jon G.

That is correct. The 12V hot lead doesn't have anything to do with activating the brakes (unless you have a wirelesss controller that draws power from it). We do recommend installing the 12V power when installing a brake controller though because a lot of trailers that require the 7-Way setup draw 12V power for some reason or another. Might as well run 2 wires while you're underneath the vehicle so you dan't have to get back under there at a later date to install the 12V power.

Reply from Todd

So if its blowing a fuse when I hook up blue wire it's more than likely bad grounds, or no??@JonG

Etrailer Expert
Reply from Jon G.

@Todd It could be a bad ground or some damaged wiring somewhere. Also check any connections to make sure they are clean, secure, and in good shape.

Marty W.

I have a 2016 Nissan Frontier with tow package. I have a Tekonsha POD #39523 when plugged into trailer, no green LED, when brakes applied goes red. there is 12 volts on the red wire when the brakes are applied but only getting max 3 volts on the blue wire no matter what the sensitivity knob is set at. when activating the manual lever does nt show any change of voltage at all. Does this mean the controller is bad.

Etrailer Expert
Reply from Jon G.

It could potentially mean it's a bad controller. What kind of voltage are you seeing on the black wire that's going to the controller? This should be a constant 12V so if it's anything less then that would be where your problem is at instead.

Reply from Marty W.

@JonG I'm seeing 12 volts on the black wire

Etrailer Expert
Reply from Jon G.

@MartyW Since that's the case it sounds like something is going on with your brake controller. This has a 5-year limited warranty so if you're within that timeframe you can take advantage of that. If you are further out than the 5 years or you just want to upgrade then I'd go with the Primus IQ # TK90160 which is a proportional controller (applies trailer brakes in tandem with tow vehicle) and it has a limited lifetime warranty.

Reply from Marty W.

@JonG. Thanks for your time and input, I'm looking to upgrade then. Thanks again

Kenneth T.

I have a 2018 chevy colorado with the trailering package but no brake controller. Bought one and decided to wire it in myself. Under the panel on the driverside kick plate are the four lose wires used to connect the brake controller to. Red, Black, white/blue, blue. When I connected it all up according to my truck manual, the papers that came with the controller and via [online] videos my trailer when connected is constantly receiving the Ebrake signal cause the brakes to be locked up. I believe the white/blue wire is the one that should only send power when applying the breaks. Checking it with a multimeter it reads at .50v at rest and pops up to 12v when the break pedal is applied. How would I go about fixing this wire or connecting to the appropriate wire to make this thing work correctly?

Etrailer Expert
Reply from Jon G.

@KennethT While I can't speak to the wire colors you are seeing right now, I can speak towards attaching the aftermarket wiring to your truck. Most aftermarket wiring harnesses use the same colors so I would use the connections below: Blue - 7-Way Output to Trailer Black - 12V Power White - Ground Red - COLD Side of Stop Light Switch (only gets hot when brake pedal is pressed) It sounds like you might have something wired incorrectly so you'll want to make sure everything is connected per function as opposed to per wire color.

Ronny

Witch wire is cold side brake switch on 2016 2500 HD with built in brake box?

Etrailer Expert
Reply from Jon G.

I don't know right off-hand what the wire color is but you should be able to find out by using a circuit tester and seeing what wire gets hot only when you press the brake pedal.

Larry

2020 Durango R/T having problems locating the cold side of brake switch, have 3 wires going to switch found the hot wire but unable to figure out which wire is the cold side, using a test light to check but neither wire turn hot while pressing the brake pedal

Etrailer Expert
Reply from Jon G.

Does your tester use an LED light or an incandescent light? We've found at times that the LED option works better because the voltage can be on the lower end. If you absolutely cannot find the cold side of the brake light switch then you might want to install the Universal Stop Light Switch # RM-751000 .

Christian T.

j'ai un GMC terrain 2017 et j'aimerais savoir quel est le fil sous mon tableau de bord qui me donnerais le signal pour activer mon controlleur de frein. Merci

Etrailer Expert
Reply from Jon G.

I'm not seeing anything in the owner's manual about what wire color you need to be looking for. You'll need to use a circuit tester to see what wire gets hot only when your brake pedal is pressed.

Rick H.

Simular question as most others. My RV has the 7 blade and only four wires. Under the dash has the trailer connection. 4 prong. Can I run a new blue wire to the controler by cutting the blue wire from the controler and connecting the new blue at that point. That makes the blue all the way to the trailer connector?

Etrailer Expert
Reply from Jon G.

If you were to route your own 10 Gauge wire from the controller back to the 7-Way that would work, yes. If your RV has the 4 wires under the dash though you may have some of that wiring already ran so it's worth taking a look. Typically when there are loose wires like that you will find the rest of the bundle of wires somewhere on the driver's side frame.

Bruce B.

I have a 2008 dodge 1500 ram my trailer brake started popping circuit breaker when brakes were hit I got to checking with a test light at the 7 pin connector and the one that go's to the trailer is hot all the time I cant figure out what is causing this I have used it for about 5 years the truck has the factory connector under dash and the break controller came with the harness to plug into it any help would I could use it will also pop breaker if you ground it to pin in 7 pin connector

Etrailer Expert
Reply from Kef G.

It sounds like you might have a short somewhere. Check your wires (starting with the black 12V wire) for any frays or damage. If you find any, make sure to replace those wires. Also, if you haven't already, you should replace the circuit breaker as well.

Sharon

I have a 2005 Toyota Sequoia that has no wires for towing. I have already put a hitch on it but now have to figure out how to hook it up when there is no wires. Please help

Etrailer Expert
Reply from Kef G.

@Sharon You'll need a universal wiring kit that splices into some of the wires in your vehicle to gain the functions of a 4-way. For your Sequoia, we have part # 119147KIT .

Dtf

Followed this exact diagram and got my 2005 BMW X5 wired up with a Prodigy P3 controller. Only difference is I picked off the brake signal from next to the battery off the X393S plug, PIN 10. Can't believe I got this thing wired up for about 200 bucks by myself, thanks guys.

Etrailer Expert
Reply from Kef G.

@Dtf Glad to hear you got everything up and running!

Ron J.

I have a '98 Tahoe. I'm having trouble reaching the wiring at the break pedal switch to patch in the red wire from the brake controller. Is there an alternative area where I can tap into the cold wire besides under the dash?

Etrailer Expert
Reply from Kef G.

Unfortunately, there isn't a better place. However, you may be able to reach the wires with a pair of long tweezers or pliers. You can usually find these kinds of tools at your local hardware store.

Joe F.

According to diagram blk lead is power for unit then sends signal to trailer wat is 40 amp cb for? Blk lead has a 20 cb

Etrailer Expert
Reply from Jon G.

The 20A circuit breaker is for the power wire on the brake controller while the 40A circuit breaker is for the power wire that goes from the battery back to your trailer via the 7-Way.

Alex H.

Why are you using a 40A circuit breaker in all these diagrams? If running a 12g duplex wire its only good to 20A.

Etrailer Expert
Reply from Jon G.

We actually use 10 gauge copper wire for that part of the installation. The duplex wiring in the # ETBC7 wiring kit is both 10 gauge.

Bob J.

1) I have a Prodigy P3 controller that I want to wire into a 2020 Pacifica Limited. The wires at the brake pedal switch are a very small gauge. should I pick up the brake light power for the controller there or somewhere else where there may be a larger gauge wire? 2) There are three wires at the brake light switch. Are the left and right stop lights powered separately from the brake light switch?

Etrailer Expert
Reply from Jon G.

1) If the wires you're seeing are no smaller than 16 gauge then you should be just fine. 2) I'm honestly not sure if they are on their own circuit or not. I would kind of doubt it though since they all would be activating at the same time.

Brian B.

I have a 2013 Town & Country Touring L that already has the 7 pin connector installed. Would there be a spot under the driver side panel that would already have the brake controller wires? Thanks!

Etrailer Expert
Reply from Jon G.

It doesn't look like your 2013 Chrysler Town and Country would have come with an OEM connector which means your 7-Way is aftermarket and you'll need to essentially have the # ETBC7 wiring to install a brake controller.

Jack T.

I have an RV on a Mercedes Benz Sprinter Chassis 2021. i would like to connect a Tekonsha controller. Controller has a 4 pin connector . Thanks

Etrailer Expert
Reply from Jon G.

If you have a 2021 MB Sprinter 2500/3500 chassis then you can use the adapter # 3063-P to plug the controller into the plug under your driver's side dash if you have the factory tow package. If you don't have the factory tow package then you'll need the pigtail # # 20127 as well as 4-way and 7-way connectors. You may also need the stop light switch kit # RM-751475 to get the brake light switch signal for the controller.

Dave O.

I have a 2017 GMC Acadia Limited. Before I bought it there was a receiver hitch and a GM 7-pin connector installed. The fuses and relays for the trailer are also installed in the engine fuse block. However, there are no leads, and no socket for a brake controller. Is kit ETBC7 what I need to install a controller? Thanks.

Etrailer Expert
Reply from Jon G.

I looked in the online owner's manual at the brake controller section and it says that you should have some blunt cut wires above the parking brake assembly. The bundle should include the follow colors: Blue - To the trailer Red/Black of Red/Blue - 12V power White/Blue - Brake light switch Black - Ground Let me know if you can't find these and I'll help you out further.

Reply from Dave O.

Thank you. After taking the panel out multiple times without finding it -- I did this afternoon. It is a connector near the parking brake. It was taped back with electrical tape and I didn't realize it was an addition and not part of the bundled wires. Now I have quite a few choices for a controller. Thanks again.

Etrailer Expert
Reply from Jon G.

@DaveO Happy to help! You might consider checking out the Prodigy P3 # 90195 as it's very easy to use and a popular choice for towing.

Steve G.

I have a Tekonsha Prodigy (purchased in 2007) that I used in my old 2006 Dodge truck, I now have a 2019 Ram 1500 (new body style), can I use my “old” Prodigy with my new 2019 truck ? if so, which wiring harness would I need to purchase ? thanks for your response.

Etrailer Expert
Reply from Jon G.

Yes, you can install your Prodigy brake controller using the Wiring Adapter # 3024-P for your 2019 Ram pickip.

Zach B.

I bought a 2016 Chevy Duramax Diesel shuttle/passenger bus 3500. I purchased a wireless trailer brake system that I mounted inside my trailer. There is a 7 pin connector attached at the back of the bus, but once I hooked up my trailer and didn’t receive power to my brakes I noticed it was only a flat 4 pin setup. There’s a 12 gauge blue and red/white wire taped underneath the steering column. I checked the red/white wire and it does in fact have 12v power. Is safe to say I can use these to wire back to the 7 pin?

Etrailer Expert
Reply from Jon G.

You probably could make that work but you'll need to find a way to route it back outside so you can attach it to your 7-Way. It'll probably just be easier to make a connection directly to your tow vehicle battery and then route the wire underneath the vehicle, keeping away from hot or moving parts. To accomplish this you can use the kit # BRK-ELECKIT which comes with 10' of wire and some additional things for the installation. You'll likely need more than 10' of wire though so be sure to add part # 12-1-1 to your order which is 12 gauge wire that we sell by the foot.

Adrian P.

I have a Tekonsha primus IQ2 and my vehicle does not have a fancy adapter thing to plug into. My question is the 4 wires coming out of the controller can you tell me where they are supposed to connect to red blue black white Thank you in advance

Etrailer Expert
Reply from Jon G.

Red - COLD Side of Stop Light Switch (only gets hot when brake pedal is pressed) Blue - 7-Way Output to Trailer Black - 12V Power White - Ground

Randy

good morning one of our service trucks is a 1997 f350 dump the wiring harness for the brake is under the dash near the ashtray. the brake controller was not engaging so I bought a new hopkins controller. when I plugged it in I got the e1 error long story short I could not find the ground or short so I rewired the entire controller wiring by passing the old harness. and rewired the plug in I still get the e1 error but the brakes engage I can't put the truck in service until the digital read out shows engagement thoughts? oh the traile is a brand new superior oversize covered trailer thanks for the help

Etrailer Expert
Reply from Jon G.

Try checking out the connector on your F-350 for the trailer. Make sure all of the wires are in good working order - especially the wire for the brake controller. I know you said your trailer is brand new but it wouldn't hurt to double check your trailer wiring. You can confirm that it's good by hooking the trailer up to another one of your trucks.

Reply from Randy

@JonG thanks checked the trailer on another vehicle worked perfectly. I will have the truck side reworked and let you know thanks

Etrailer Expert
Reply from Jon G.

@Randy Thanks for the update!

Mirek

I have a 2013 Hyundai Sonata I am towing pop up RV with (Starcraft about 1400 lbs). This is an upgrade trailer for me as I started with a little coleman (900 lbs) that did not have electric breaks. My question is what does it take to have the electric break wired on this trailer. I have the 7 way to 4 way connection and trailer lights and blinkers work. I have several extra wires (blue, black, white i believe) with the connector. If i purchase a break controller can I use the current wiring or does a cable need to be run again all the way to the battery. I have a 4 way plug coming out of my trunk. I purchased 7 way to 4 way plug set up because the trailer has 7 way plug. Can I do this myself or should i take it to a car electrician or a shop ? I have no clue about any of this but if it is very simple I could probably get the job done :)

Etrailer Expert
Reply from Jon G.

It sounds like you have something similar to the Hopkins Adapter # 37185 installed on your 2013 Hyundai Sonata. If you're wanting to install a standard-style brake controller then you can just use the Wiring Kit # 5506 to finish up the connections for the 7-Way. If you want to go with the Curt Echo Brake Controller # C51180 instead then you can just use enough 10 Gauge Wire # 10-1-1 to go from your connector all the way to your positive battery terminal. The only other thing you'll need is a 30A Circuit Breaker # PK54530 in-line on that same wire.

Roy ..

Have a new 2020 Silverado 1500 truck did not come with factory installed trailer brake switch . So I ordered the original switch that fits in dash and installed it but it will not connect to the wiring harness the dealer provides with new truck so my question is how does it wire up . Or how do I find where to wire it in.

Etrailer Expert
Reply from Jon G.

I'm not sure how the OEM brake controllers install so you might need to reach out to a dealer about that, but the aftermarket brake controller harnesses, like part # 3016 , connect inside the junction box near the emergency brake pedal on your pickup. You can check out the installation instructions on the 3016 product page for a visual.

Jp

I have a 2005 Ford E450 RV. I have installed a brake controller under the dash using the existing vehicle plug dedicated to the controller. I have an existing 7 blade connector at the rear of the RV with four wires for stop, turn and running lights. issue I have is finding the connectors that are set up for the tow package namely the blue and orange wires that come out of the wiring harness. Did Ford put in a brake controller and rear 7 pin connection but didn't route wires for brake and voltage?

Etrailer Expert
Reply from Jon G.

For the Ford vans (which includes the E-450 chassis) you should be able to find the clue and orange wires like what is mentioned in the linked article. I will say that sometimes on RVs the wiring or other parts can be different so if you absolutely cannot find this wiring then you'll need to run some of your own wiring and make your connections. You can do this with 10 gauge duplex wire # 10-2-1 , a 40A circuit breaker # 9510 , and whatever ring terminal size fits your battery.

Reply from Jp

@JonG thanks, looks like i'll need some wire

Chris H.

I'm installing a brake controller and a 7 way plug on a 1995 Ford F Super Duty, single cab flat bed dually. I have a 3035 wiring harness adapter to connect the brake controller to the trucks wiring under the dash/radio. I believe i found the harness it plugs into. My question is- if i use the 3035 adapter, do i still need to install the circuit breakers and run two wires back to the 7 way plug? I've already wired the 7way to the truck 4 way, minus the blue/electric brake and black / power wires. I am not seeing any other wires run to the rear of the truck, except the 5 factory wires for rear lights. No brake or power wires.

Etrailer Expert
Reply from Jon G.

So a 4-Way trailer connector only carries the light functions for a trailer, if that's all you have on your 1995 Ford pickup then yes, you will need to run some additional wiring. The good news is that it sounds like you have a factory installed 4-Way and that you also have the factory wiring for a brake controller already existing on your truck. This means that instead of running the wires all the way to your cab you should be able to connect them to the orange and blue wires that exist in the bundle of wires near your driver's side frame behind the rear wheel. According to the instructions for the Tekonsha Wiring # 118242 it does look like you'll still need to install fuses and relays. I recommend checking out those installation instructions as well as this helpful article on wiring.

Reply from Jp

@JonG I've looked at each bundle even unwrapped the harness to look at the colors, stretched them out but the connector wires are MIA. i'm thinking since there is a 7 pole connector welded to the receiver that it is factory installed and they didn't install the connectors I'm searching for. But the wires should be accessible somewhere back there. thanks for the input

Sorin N.

The instructions say to connect the hot lead and the e-brake controller directly on the battery. This would add a constant drain to the battery when engine (alternator) is not running. What's the purpose of providing a "hot lead" to the trailer that can potentially discharge the vehicle battery? Isn't better to run those trough a relay that provides power only when ignition is "ON/Aux"?

Etrailer Expert
Reply from Jon G.

Great points! Any trailer brake controller that I've looked into has such a small amount of draw when it's not being used that it would take a few weeks of the car sitting parked for it to completely drain the battery. If you plan on keeping your trailer hooked up to your vehicle and you don't want the trailer battery to drain the vehicle battery then you can either install a smart charger or you can install an Isolation Solenoid # TR118665 which will cut power when the ignition is off.

Reply from Sorin N.

@JonG Thanks for the suggestion!

Jim C.

I have a 2008 tundra that doesn’t have the factory tow option. It was wired for a 4 pin blade receptacle. Now I’m trying to wire it for a 7 pin connector with trailer brakes. I installed the 7 pin receptacle on the bumper and plugged it into the plug that I disconnected from the 4 pin. I already installed the brake control unit in the cab. My problem now is I don’t have the last 2 wires ( the electric brake wire and the power wire ) running from the front back to the plug in the back. All my blinkers and lights are hooked up and work. I just don’t have the last 2 wires. Is there a harness or do I have to tap the lines from the back of the control unit. Thanks

Etrailer Expert
Reply from Jon G.

Since it sounds like you already have the connector portion of the # ETBC7 wiring kit, the wires that you're looking for come in the kit # 5506 . This also includes circuit connectors, butt connectors, and ring terminals.

Reply from Jim C.

@JonG thanks.

Greg V.

All my my trailer connections are hardwired. So, if I run the Red wire from the brake controller to the back of the vehicle and hardwire splice it into the same line as the brake lights (connecting the vehicle and trailer plug), is this effectively the same as connecting it to the wire right behind the brake pedal? I'm getting blinking in my trailer lights when all brakes, running lights, and indicators are all enabled simultaneously. Can't figure out the problem!

Etrailer Expert
Reply from Jon G.

If you're having issues with your trailer lights then you'll want to take a look at the light circuits and make sure that they are all connected securely and that all of your grounds are installed on a clean, bare-metal surface. The brake controller will only send power to the trailer brakes. The only time that a brake controller can mess with the trailer lights is when there is a mis-wire or some corrosion somewhere that causes the brake controller signal to leap over to the other circuits.

Reply from Jim R.

@JonG So, is he correct in running the Red wire from the brake controller to the back of the vehicle and hardwire splice it into the same line as the brake lights? I am in process of installing a 90160 Primus IQ and was going to run the wires this way also. Thx

Etrailer Expert
Reply from Jon G.

@JimR As long as the red wire is connected to a circuit that only gets hot when the brake pedal is pressed it's okay.

Trent

With a constant 12v going from the positive terminal to the 7 pin connector, and the brake controller going to the positive terminal as well (via circuit breakers) my brake controller on my ram 2500 is lit up as it's registering a trailer connected. With those wires going straight to the positive shouldn't they be spliced in to a keyed-on positive wire?

Etrailer Expert
Reply from Chris R.

The brake controller, although wired directly to the battery, will eventually go into a sleep mode with the vehicle's ignition turned off. There's no need to wire it to a keyed power source.

Glenn W.

I have a 16 ft jayco starcraft caravan with electric brakes.I have fitted a tekonsha primus iq brake controller to my tow vehicle.The controller is showing that there is a short in the wiring.On unplugging brake magnets the wiring is clear.Each magnet is measuring 3.4 ohms and testing from the tow plug the measurement is 1.7 ohm.The brakes are operating as they should be but I am getting the 5H flashing on the screen.How do I rectify this problem.

Etrailer Expert
Reply from Chris R.

The short may be coming from somewhere else. Inspect the 7-Way connectors, both on the tow vehicle and on the trailer, and look for any corrosion or debris built up inside the pins that needs to be cleaned out. This can sometimes lead to a short on the brake output circuit. With regards to the controller installation - was it completely hardwired or were you able to use a plug-in adapter harness?

Dan

I have a 2000 chevy signal cab short bed. I have the Tekonsha Voyager brake control. Cannot get to work. With plug supplied by gm when truck was new.

Etrailer Expert
Reply from Chris R.

Can you tell me what specifically isn't working with the brake controller? Is it not powering on at all or is it not working to engage the trailer brakes?

Reply from John H.

@Dan Check the two fuses by the studs in your underhood fuse box. You should have a fuse next to each stud and there should be ring terminals with wires coming off. One goes to your brake controller plug in the cab and one goes to your 7-way connector at the back of the truck. I believe the stud closest to the positive battery terminal is for the brake controller plug.

Ace

One question: WHY do you have a live wire (from B+) going directly to the trailer brakes, while the brake controller is supplying the brakes with current, and the lights have a separate system? We have a simple resistance-based brake controller and old-fashioned hydroelectric brakes on the trailer. The only way to make the whole system work in our case is to ground that wire to the firewall/frame! The ONLY power supply to the trailer brakes is via BLUE wire from the controller! Now everything works!

Etrailer Expert
Reply from Chris R.

I'm not quite sure what you mean. There should only be one power wire going to each brake assembly - and that is the blue brake output wire that you mentioned. The 12V hot wire would connect to a trailer mounted battery bank to provide a maintenance charge during travel - it would not be tied to the trailer brake system.

Reply from Ace

@ChrisR Oooh, OK, gotcha! Guess I forgot how trailers are typically wired- our battery bank is powered by solar. Thanx for clarifying!

Etrailer Expert
Reply from Chris R.

@Ace No problem!

Reply from John H.

@ChrisR There should be a wire going from the battery to the breakaway and then to the brake output wire. This would activate the brakes in a trailer breakaway situation.

Cody M.

Working on a 2013 Ford F550 with a Utility bed and hoist. Im trying to install a new 7 way plug and it was all going well except I can't seem to find my brake wire. All of my wires tested negative so I have to run wires from the LED lights to the pickup end itself. I found my brake wire I believe but still no power from the original harness. How do I run a new brake wire from the brake switch? Thanks

Etrailer Expert
Reply from Chris R.

Are you referring to the factory trailer harness on your F-550? The brake and turn signal circuit should be sent along the same wire (trailer wiring is combined), so I would test the wires you already found for the turn signals and see if they also carry power with the brake lights illuminated.

Miguel

Hi, I'm installing a Reese towpower 8508211 brake controller on a 2019 VW Jetta everything is pretty much done but the only problem I had when trying to connect the red wire to the brake switch there were no wires on the brake pedal so what I did, I tap in to one of the wires that runs to the brake tail lights that runs from front to back on the side of the door this wire only gets power when you press the brake pedal. On the brake co troller screen I get 2 dots and when I activated manually I get an N.C. on the screen I wounder if my installation is correct? Thank you

Etrailer Expert
Reply from Chris R.

Are you testing the controller with a trailer actually hooked up? The "N.C." means "no connection", so that would be a normal message if the trailer isn't plugged in.

Reply from Miguel

@ChrisR Looks like I got them to work I had both wires from the brakes connected to positive and no ground, so now I have one positive and one ground to each brake, both tires are locking up on the air but not when I'm driving the car at 25mph I can barely feel the trailer to engage the breaks all this with a max (10 & b1)at the brake controller do you think this problem has to do with any wiring issue or I need to break in my new pads in order to performed to the fullest. Thank you for your help

Etrailer Expert
Reply from Chris R.

@Miguel If you have new, self-adjusting brake assemblies they may indeed just need to be broken in a bit. Take the trailer up to an empty parking lot and just engage those brakes a bunch - each time you do this they'll essentially adjust a bit more until you have ideal braking.

Don J.

Brake sense color and location for 2004 mercury mountaineer premier 4.6l v8 awd

Etrailer Expert
Reply from Chris R.

If your Mercury Mountaineer has the factory 7-Way connector at the bumper there should be a built-in brake controller port behind the dash with which you can use the Plug-In Adapter # 3035-P (if you have a Tekonsha or Draw-Tite controller). I wasn't able to track down info on an exact location, but typically these ports are to the left of the steering column, hidden a bit behind the dash. You might even check with a local Ford dealer to see if they have any information on this.

Charles B.

I have a 2019 canyon, I bought a hopkins impulse controller. Can you help with the wiring please. I have to use it in 2 days, please advise

Etrailer Expert
Reply from Chris R.

Your Hopkins Impulse controller can be wired right into the factory harness under the dash. There isn't a plug, but all the needed wires are already present. They should be labeled by function. Coming from the Impulse the red wire will go to the brake input circuit, the black wire is for 12V power, the blue wire is for brake output (to the trailer), and the white wire is for ground.

Darby L.

What color wire do I need to tap on brake pedal of a 2008 Nissain Armada

Etrailer Expert
Reply from Chris R.

Based on my research it actually looks like your Armada should come equipped with a factory port for plugging in a brake controller (whether or not it has the tow package) - so you shouldn't need to look for the right brake switch wire for a hardwire install. For example if you're looking to install a Tekonsha controller like the Prodigy P2 # 90885 , you would just need the Adapter Harness # 3050-P for a plug-and-play install. If you don't have the tow package you would add the 7-Way Kit # N40975 .

Reply from Darby L.

@ChrisR. Brak controller will not work with plug and play harness. That is why I am going to hard wire it.

Etrailer Expert
Reply from Chris R.

@DarbyL I see. I wish I could track down the right wire color for that circuit, but the best method will be to simply test the wiring behind the pedal to see which one only gets power when the brake pedal is depressed (and no power with any other function). This is where the red wire from the controller will connect.

Chade

We have a 2019 Durango that does not have the towing package so I will need to wire directly, however I am unable to find the wire for the break sense (stoplight) switch. Do you happen to have the color and location of the wire? I have to assume it's in the wire panel just behind the ebrake pedal but I can't find any wire that is only hot when the break is depressed.

Etrailer Expert
Reply from Chris R.

I really wish I could track down the right wire color, however I wasn't able to find a diagram for your '19 Durango. On some vehicles finding the cold side of the brake light switch can be difficult- if you can't find a wire behind the brake pedal that only gets power with the brake pedal depressed, you might need to tap into the 3rd brake light or even use the Stop Light Switch Kit # RM-751449 for this signal.

Bill

Does the connection from the brake light switch carry a ground or a positive 12volt to the controller. Would connection to the center mounted brake light on a ford transit work. How much currant does this connection draw as these are very light guage wires.

Etrailer Expert
Reply from Chris R.

If you're able to access the 3rd brake light and you find the circuit that only gets power when the brake pedal is depressed (and no power otherwise) then you can tap into that circuit for the controller's red wire. Sometimes this is necessary if there isn't an adequate wire to tap into behind the brake pedal. For 12V power (to actually power the controller) you'll need to connect directly to the battery in your Transit.

Trent

Which color wire on my break pedal wires is the power to the brake. 2003 gmc Sonoma ext 3 door no tow package.

Etrailer Expert
Reply from Jason S.

I tried looking up your particular model for color. The closest vehicle I could find the color diagram for which I believe has the same wiring harness is the Chevy S10. On that model the wire color you'd be looking for is white. To confirm this or to diagnose your vehicle's brake wire, you will want to use a circuit tester like # PTW2992 to test the wire for power. You should only see power when the brake pedal is pressed and no power on the wire when the brake pedal is not.

Dave L.

Thanks for the helpful article. Questions:1. The brake controller is wired directly to the battery in the diagram. I could postulate safety reasons for this i.e. not to lose brakes if the engine quits or needed to apply brakes with the truck off but Is it acceptable to wire to an accessory with appropriate relay switch position. Seems like you would have a good potential to drain the battery if you left the controller on with the vehicle off.2. You used circuit breakers in this application. Is there a reason that circuit breakers were used in lieu of cheaper / simpler fuses. Again I could postulate that maybe you would hope that the breaker would reset if the fault cleared and still retain brakes.....? But you would still lose the brakes for some period of time whether the breaker tripped or the fuse blew...….

Etrailer Expert
Reply from Jacob H.

If the break controller is operating properly, it would take a very long time for it to have any affect on the battery. Using a breaker is so that instead of having to replace the fuse when ever it blows, the breaker will trip and reset. You shouldn't have any issues with fuses or breakers if everything is wired correctly. If the breaker is not resetting then it will need to be replaced just like a blown fuse.

Reply from Sorin N.

@JacobH @DaveL I had the same question as above. I am especially worried about the "hot lead" that will be permanently tied to the trailer connector and the trailer (when towing). So when we stop somewhere temporarely, we absolutely need to disconnect the trailer, to avoid a battery drain, even if we don't un-hitch?

Etrailer Expert
Reply from Jon G.

If you are stopping for a short period (like at a gas station) you'll be just fine, but if your stop will be longer like overnight then you'll want to either disconnect the trailer connector or install a battery isolation solenoid # TR118665 which disconnects that 12V power when your ignition is turned to off.



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