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Brake Controller 7- and 4-Way Installation Kit (ETBC7)

Custom Fit Trailer Brake Controller

The Brake Controller Installation Kit, or ETBC7, includes everything necessary for converting your 4-way connector to a 7-way connector in order to use a brake controller to activate the electric brakes on your trailer.

Why do I need an ETBC7?

If you do not have a 7-way plug on your vehicle, but want to use your electric trailer brakes, you will need to upgrade your wiring to support the brake controller. The ETBC7 includes everything you need to make this upgrade (once a working 4-way connection is installed).


Parts Included:

7-way trailer connector, which includes a 4-pole adapter plus 4 additional wires that connect to your vehicle to complete the installation

Mounting bracket and mounting hardware that secure the 7-way connector to the vehicle bumper or hitch; self-tapping screws mount the bracket to the vehicle and the trailer connector to the bracket

Black loom, which is a hard plastic tube that covers the 12-volt hot lead and brake wire connections, giving your installation a professional appearance and extra protection

Gray duplex cable that houses 2 wires that will become the 12-volt hot lead and electric brake wire, which run from the trailer connector to the front of the vehicle

Circuit breakers, which are used to protect electrical components against overload (3 are provided, 2 are used)

Butt connectors for securing connections between wires

Ring terminals, which attach to the ends of wires and hook around battery posts and circuit breakers

Quick splice wire connectors, which are used to quickly connect wires together

Zip-ties, which bind loose wires together and keep them in place, away from moving parts and exhaust system components

Circuit tester

Tools needed:

Brake Controller 7- & 4-Way Installation Steps

The ETBC7 installation kit works with your existing 4-way connector and brake controller. If you do not currently have a 4-way connector on your vehicle, you can use the Vehicle Wiring Fitguide to locate the custom-fit wiring harness, and the Brake Controller Fitguide to find the brake controller for your application. Since this kit supplements your brake controller, please review the instructions included with your brake controller before beginning the installation.

mounting 7-way connector plug bracket

1. Find a suitable location to mount the 7-way connector plug.

4-pole adapter plugged in to 4-pole trailer connector

2. Plug the 4-pole adapter coming out of the 7-way connector into the vehicle's 4-pole trailer connector. Secure this connection with a zip-tie.

white wire grounded to vehicle frame

3. Ground the 7-way connector by screwing the white wire with a ring terminal on it into the frame of the vehicle. If you will be using your reverse trailer lights, attach the yellow wire coming out of the 7-way connector to your reverse light wire, using one of the quick splice wire connectors included with the kit.

separating the two wires inside the duplex cable

4. Make a small cut in the rubber sheath of the duplex cable and slightly separate the two wires inside, being careful not to nick these wires.

using butt connectors to attach wires

5. 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. Use electrical tape to keep the wires together and then install the black loom over the wires.

routing duplex cable to engine department

6. 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 moving parts that might pinch the cable.

separating wires in duplex cable

7. Once the duplex cable is under the hood, you will need to separate the white brake wire from the black 12-volt hot lead. Cut away the gray sheathing as before, being careful not to nick the wires.

separating the duplex wires

8. The black 12-volt hot lead will stay under the hood, where it will be connected to the positive post of the battery by using a 40-amp circuit breaker. You will then route the white brake wire through the firewall (on the driver's side under the dash) into the vehicle, where you will connect it to the blue wire on the brake controller.

drilling an access point in firewall

9. Look for a grommet or knockout in the firewall to route the white brake wire into the cab. If none is available, you can drill a hole on a section of the firewall where there is no obstruction on either side. You will need to drill a hole to install a grommet large enough for the 3 wires that will pass through:

blue wire connected to white wire

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

mounting circuit breakers

11. Mount the 20-amp (or 30-amp; see brake controller instructions) and the 40-amp circuit breakers in a safe location under the hood. In this photo, you will see it was mounted to the right of an existing ground wire on the firewall.

12-volt hot lead connected to 40-amp breaker

12. The 12-volt hot lead from the trailer connector in the duplex wire (black) gets routed to the 40-amp breaker. Cut the extra wire and add a ring terminal. Attach to the AUX/silver post of the circuit breaker and route a wire from the copper post of the circuit breaker to the positive post on the battery.

brake controller

13. The black wire coming out of the brake controller is the brake controller power supply. It will be too short to reach the battery, so you will have to use excess wire from the duplex cable to complete this connection. Route this wire to the AUX/silver post on the 20-amp (or 30-amp) circuit breaker under the hood. Then route a wire from the AUX/copper post of the circuit breaker to the positive post on the battery.

2 wires connected to positive battery post: 12-volt hot lead and brake controller power supply

14. There are now two wires connected to the positive post: the 12-volt hot lead and the brake controller power supply.

15. The white wire coming out of the brake controller is the ground wire. Route this wire to the negative post on the battery. It will be too short to reach the battery, so you will have to use excess wire from the duplex cable to complete this connection.

brake stop light switch wire connected to red brake controller wire

16. Inside the cab, only one connection remains. Find the wires connected to the brake stop light switch at the top of the brake pedal. Using a circuit tester, test the wires to locate the wire that carries a signal only when the brake pedal is engaged. Using a quick splice wire connector, connect that wire to the brake controller red wire.

excess wires zip-tied

17. With the brake controller mounted and connected, zip-tie any loose, excess wires underneath the dash and under the vehicle. Clip any excess material from the zip-ties. Do not allow the wires to interfere with the brake and gas pedals and keep them away from areas that get very hot. Using a circuit tester, test all wires to ensure that they are getting power before you hitch up your trailer.

ETBC7 Installation Diagram

# ETBC7 Installation Diagram

Connector Diagram C57672

Connector Diagram for # C57672 (included with # ETBC7)

For more information on brake controllers and wiring, see the following:

Updated by: Amber S.

Last updated: 6/5/19



2012 Acura Mdx. Need to know the wire colors for the battery, brake and reverse wires in the trunk. To wire this 7-way socket.

David B.


Here are some help articles to guide you along. They list the "common" color guides for wires but this is not always the case and sometimes they are different. If so you will need to get a circuit tester and test the function of each wire.

Tom E.


I have a 2006 GMC 5500 (former UHaul truck). It has a dedicated cable with 7 pin RV receptacle but no brake controller. All other functions (lights etc are functional). There is an unused 4 wire connector under the dash on the driver's side, but the wires are small, perhaps 22 ga. I can't convince myself this is correct, unless relays are in the circuit. The stoplight switch wires go into a harness immediately at the switch and very difficult to access. I plan on using a Redarc liberty as I have used previously. Any advice for me?

Les D.


Typically the four wire connector has: White to chassis ground Black 12 volt from battery with inline fuse Red from brake pedal switch Blue output to trailer brakes. Use your volt tester to see if these operate as expected. The voltage on blue wire will go up as brake pedal is depressed further.

Tom E.


@LesD I have previously done the above. I have brown, yellow, dark blue and light blue. With the ignition key on the brown and yellow float at around 6V. ??? With the brake pedal depressed there is no change to any wire. I have installed a number of controllers and never encountered a problem like this. I have a good amount of automotive experience in y 81 years. Maybe someone can shed some light on this.

Les D.


After further research I find people saying to not use a standard 4 wire pigtail with this vehicle. I am going to suggest you wire this manually following the recommendation of the GM bulletin I have posted below.
See All (6) Replies to Tom E. ∨



I own a 2008 Dodge Ram 1500. It doesn't have the plug for the brake control so I had to install it myself. Locally, they wanted to charge me $250 to $400 to install it but I knew I could do it. I purchased the wiring from U-Haul, very reasonably priced. I followed the diagram above and now I can pull my 2018 Dutchmen travel trailer. It took me three hours to run the additional wiring, mount the breakers, attach to the battery posts and drill a hole for the brake control wires. Thanks

Les D.


@Samanth I see that (for your 2008 RAM truck) we provided the expert research on how to add a round 7-way trailer lighting harness, a kit to make getting everything neccessary the first time, detailed installation instructions with pictures, and a large wiring diagram. What more could we have done to earn your purchase?



I have a 2010 Ford expedition XLT and I don’t understand where I hook up the brake assist wire coming from the plug to the brake controller because my brake controller is plugged in it’s just a plug and play

Les D.


Which brand and model of brake controller are you using? I suspect you are talking about the blue brake controller output wire. Did your truck already have a 4-way or a 7-way connector?



@LesD yes I am talking about the blue brake controller wire,it has the 4-way

Les D.


@Andy When you say that your brake controller is plug and play, I imagine you mean that your brake controller came with a special cable where one end plugs into the brake controller and the other end plugs into the vehicle's brake controller port. Those four wires connecting to the brake controller port are black for 12 volts from battery, red from the brake pedal switch, white which will go to a chassis ground, and blue that will go to the 7-way connector installed by the factory for braking voltage/signal. HOWEVER, since your truck did not come with a 7-way connector that connection goes no where. Snip the blue wire out of the adapter cable, and run it all the way back to the 7-way you installed aftermarket and connect it to the blue wire there so that trailers plugging into your 7-way will have their brakes energized.
See All (4) Replies to Andy ∨

Matthew M.


I have a 2000 Coachmen sportscoach on a Freightliner frame I am having trouble finding what I need for this electronic brake control. I already have a four prong installed any help would be greatly appreciated

Les D.


@MatthewM I would like to help with this question. First a few questions. Which model Sportscoach do you have - 380MBS? When you say, "electronic brake control" I assume you mean a supplemental brake that installs in the vehicle being towed. Like the Roadmaster # RM-9400 linked below? You say that you have a flat 4-way connector. It's hard to conceive that a coach this size does not have a round 7-way connector. I assume you have a 2 inch square hitch receiver? Double check this for us please.

Matthew M.


@LesD u have a 2000 380mbs it only has 4 flat pug with 2" hitch. I am looking for plug and play electric break assist box. My trailer has electric brakes and I guess I need one of these to apply those trailer breaks



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