Brake Controller Installation on a 2008 GMC Sierra and Chevy Silverado
Also applies to all 2007 New Body Style GMC Sierras and Chevrolet Silverados
Before installation begins, you will need 3 components:
- Brake controller
- Brake controller adapter - Draw-Tite 20127 , Valley V30520 or Tekonsha 7894
- NOTE: Adapters are only required for brake controllers with a quick disconnect feature. Brake controllers with wires attached do not need an adapter.
- 7-way replacement adapter (unless already installed from the factory)
Installing the 7-Way Replacement Socket (20047)
If your vehicle already has a 7-way trailer connector, skip ahead to "Connecting the Brake Controller Adapter (20127) to the Factory-Installed Tow Package"
1. Begin at the rear of the vehicle, behind the bumper. Unplug the round 7-pole factory-installed plug that leads to the outside of the bumper.
2. Move around to the outside of the bumper. Remove the square knockout panel, located to the left of the license plate.
3. With the square knockout panel removed, slide the 7-way replacement socket (20047) into the knockout hole. Line up the notches on the replacement socket with the notches in the knockout hole. Then rotate the replacement socket clockwise, locking it in place.
4. Return to the area behind the bumper. Insert the round 7-pole factory-installed plug (removed in step 1) into the 7-way replacement socket (installed in step 3).
NOTE: It's always a good idea to use dielectric grease to help seal electrical connections. Water intrusion of the 7-way connector can cause shorts and corrosion in the wiring. In particular, shorting of the brake controller blue power wire may set off warning codes in the brake controller. Dielectric grease will keep moisture from compromising these connections.
Connecting the Brake Controller Adapter (20127) to the Factory-Installed Tow Package
For brake controllers without the quick disconnect feature, no adapter is necessary. If your brake controller has wires already attached to the back, skip ahead to "Mounting the Brake Controller (Draw-Tite Activator III - 5520)"
1. Below the steering column, there is a bundle of wires tied together with white tape, located left of the brake pedal. This bundle of wires is the tow package for the brake controller. Carefully cut the white tape binding the wires, and pull the wires down from underneath the steering column.
2. Connect the four wires on the brake controller adapter (20127) to the tow package wires. Follow the table below to connect the tow package wires and adapter wires using butt connectors.
NOTE: DO NOT connect the tow package orange wire to any adapter wire. Use of the orange wire may result in inadequate, pulsating and/or no braking. Simply tie up the orange wire with any other unused tow package wires.
| Tow Package | Brake Controller Adapter |
|---|---|
| Red | Black |
| Dark Blue | Blue |
| Light Blue | Red |
| White | White |
3. Using electrical tape, bind the wires together.
Mounting the Brake Controller (Draw-Tite Activator III - 5520)
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.
2. Using the screws provided, mount the mounting bracket into the dash. Make sure to avoid drilling through various components on the other side of the dash.
3. Using the screws provided, secure the brake controller into the mounting bracket.
4. Plug the adapter (20127) into the back of the brake controller (5520).
5. With the brake controller mounted and connected, zip tie any loose, excess wires underneath the dash. Do not allow the wires to interfere with the brake and gas pedals, and keep them away from areas of excessive heat.
Finalizing Connections for the Brake Controller
1. Under the hood, remove the cover for the power distribution box, located on the driver's side.
2. The ring terminal for brake controller power is located directly to the right of the power distribution box. It is taped to a wire harness between the driver-side front fender and the power distribution box. Cut the tape to release it from the harness. Then run the wire to the front of the power distribution box and hook the ring on the left post (M6 stud).
3. The ring terminal for the 12-volt power lead for the 7-way trailer connector is located to the left of the power distribution box. It is taped to a wire harness under the power brake booster. Cut the tape to release it from the harness. Then run the wire to the front of the power distribution box and hook the ring on the right post (M8 stud).
4. Tighten the ring terminals onto the posts using nuts (not provided).
5. Activate the brake controller power post by inserting an automotive style 30-amp fuse into the correct slot in the power distribution box.
6. Activate the 12-volt power lead post by inserting an automotive style 40-amp fuse into the correct slot in the power distribution box.
NOTE: Most vehicles are already equipped with the fuses listed in steps 5 and 6. However, if your vehicle does not have one or both fuses, you will need to insert your own fuses.
7. Place the cover back onto the power distribution box, and close the hood.
Help
Testing Wiring on an Electronic Brake Controller DemonstrationBrake Controller Wiring - What are the Wire Colors?Brake Controller Help
Brake Controller InformationBrake Controller Installation from ScratchInstallation Guide - 2008 Chevy Silverado and GMC SierraInstallation Guide - 97-06 Ford F-150, 99-04 F-250/F-350 Super DutyInstallation Guide - 05-06 Ford Super DutyInstallation Guide - Dodge PickupsInstallation Guide - Chevrolet / GMC 1999-2006 PickupsQuestions and AnswersRecent Brake Controller Questions and Answers
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Question:
I am trying to install a voyager brake controller on a 1996 Chevy/GMC 1/2 ton. The control box was given to me out of a 2006 chevy 1/2 ton. There were no instructions or wiring diagram. I would like to know if there is a model specific adapter or do I need to splice the wires in? The trailer plug female has been installed on the truck and works properly, the blue and orange wires are factory installed and are at the firewall, but are loose. Please help!!!
asked by: J last update: October 6, 2008
Reply:
You've already done the hard part. Those blue and orange wires are very difficult to find under the hood. Using a wiring adapter to install a brake controller will not be an option for your vehicle. You said that the 7 way connector is already installed, so you'll just need to install the brake controller. Typically, the brake controllers have 4 leads exiting the rear of the unit. The blue wire would run through the firewall and connect with the blue wire that runs to the connector on the rear of the vehicle. The red wire would run to the cold side of the brake switch. Your best bet to locate the wire to tap into would be to find the main wiring harness under the dash by the steering column. You'll need to use a circuit tester and probe the wires until you find one that only shows current when the brake pedal is pressed. The white wire would run to ground, and the black would run to a 12v power source, via a 20 amp inline circuit breaker. The orange wire under the hood is your hot lead for the trailer connector. It would also need to run to a 12v power source, using a 40 amp inline circuit breaker.
reply by: Mike
Question:
Thank you for the excellent instructions. I had no trouble installing a Prodigy in my brand new 2008 Silverado. The pictures were a great help. My question is this, the recommended power source comes from under the hood. There is a M6 post that is always hot. The Prodigy has two lights illuminated even with no connection and the key turned off or out of the ignitions switch. Is the Prodigy drawing any current while at rest and will it drain my battery? Should I install an On-OFF switch?
asked by: George last update: October 6, 2008
Reply:
The two dots you speak of will not draw enough power to drain your battery. If you plan on leaving the vehicle parked for an extended period of time, you can always unplug the harness from the rear of the Prodigy. I don't believe a switch would be necessary.
reply by: Mike
Question:
I have a 2005 Ford F250 SD with power stroke and tow Pkg., I went to install Tekonsha Primus and discovered previous owner cut out OEM trailer harness. Which color of wires do I hook up the brake control box to now? Should I tap into the wires coming off the brake pedal?
asked by: Ric last update: October 6, 2008
Reply:
At this point, the easiest thing to do would be to install the brake controller as if the vehicle was not wired. The four leads coming off the brake controller are wired as follows: The red wire would tap into the wire coming off the cold side of the brake switch located above the brake pedal. The easiest way to locate this wire is to use a circuit tester and locate the wire that only shows current when the brake pedal is pressed. The black wire would run to a 12 v power source, usually to the underhood fuse box. The white wire is grounded, and the blue wire is the brake output, and would run back to the 7 way connector on the vehicle's bumper.
reply by: Mike
Question:
I was just installing a Tekonsha P3 with 3015 wiring harness into a 2003 Silverado that appears to have a tow package. From the factory it has a 7 pin harness under the bed just in front of the rear bumper. When I plugged it in the P3 did not power up. I dont see an on button. The instructions that came with the P3 didnt say anything about hooking up anything at the underhood fuse block but to be safe I read your instructions for vehicles without a 7 wire hook up. Not that it should matter for this vehicle but I believe you have the instructions for the red and blue wires reversed on post one and two. They arent long enough to go that way and the ring connector on the red wire wont go over the fatter post. But even if I did need them that shouldnt matter. Once the key is on and fuses are in, both posts have power. So since P3 is not powering up with the 3015 harness plugged into the correct location 2nd to the left I need to know what to do next?
asked by: James last update: October 2, 2008
Reply:
It's not clear by your question whether or not you connected those wires to the posts. In order for your controller to work, they need to be connected. The red wire that powers the controller needs to be attached to the post closest to the rear of the vehicle. The other wire which provides a 12v feed to the trailer connector on the bumper would attach to the other post. Typically, both these wires are red, we just showed one as blue for clarity. As you mention, the ring terminals are differently sized, just match them up to the proper post, and make sure the applicable fuses are in place.
reply by: Mike
Question:
Im looking for a full-featured brake controller for a 2008 Touareg. Its fairly well-known that the Tekonsha Prodigy has problems when installed in the Touareg because of the way the Touareg monitors the trailers circuits for burned-out lights it sends a low-voltage signal through the cirvuit periodically. This fools the Pridigy into thinking the brakes are being applied. Im looking specifically at the Tekonsha P3 and the Valley Odyssey II controllers. Do you know of these controllers will have the same issue as the Prodigy, and if so, can they be wored to work correctly? I believe the fix for the Prodigy is to use the brake switch signal and not the brake light signal to trigger the controller.
asked by: Robert last update: October 2, 2008
Reply:
After some research, we've found that the solution is to obtain the brake signal from the brake switch, and not one of the brake lights, as you suspected. If you install your controller (whichever one you should choose) in this manner, you should have no problems. I can highly recommend the Prodigy, it is very easy to install, set up, and use, which helps make it our best selling brake controller.
reply by: Mike
Question:
How much voltage should there be at the output of the brake controller at the truck 7 pin connector. As it is right now, when the brakes are applied and held 1.9 volts show on the meter.
asked by: Harvey last update: September 27, 2008
Reply:
Are we talking about a proportional or time delayed controller? Try testing the blue wire where it exits at the back of the controller. When the brake override switch is activated, you should be seeing very close to 12 volts. Please reply and let me know what you find.
reply by: Mike
Reply:
The controller is a Draw Tite Activator, time delayed. If I set the sync and output to max and use the white wire as ground and the blue to show the voltage. When the manual override is activated it shows 11.75 volts. I wish I had a manual that would show the approximate settings for a 4500 lb trailer, maybe than I could figure it out.. As it is now set at 50 percent or halfway on the sync and output, the truck seems to do most of the braking, just by the brake lining dust that accumulated on the wheel covers and rims on our last trip..
reply by: Harvey
Reply:
So what you are telling me is that somewhere between the brake controller and the trailer connector socket on the bumper you are losing approximately 9.85 volts? Two possible culprits come to mind. First (check the easy fix first!) closely examine the trailer connector socket. You might even test the blue brake output wire where it goes into the back. If you get the ~ 11-12 volts there, you have just identified the connector as the culprit. It could be corroded, preventing a good connection. Another cause might be a pinched or frayed wire. You'll have to trace the brake output wire back from the controller all the way to the trailer connector, looking pinch points or for cracked or missing insulation on that wire.
reply by: Mike
Question:
I have a 1998 chevy cab and 1/2 4*4 pick up I found the blue wire under the bumber for electric brake,but where do I find the one up front so I can hook up controler ??
asked by: Ray last update: September 27, 2008
Reply:
That wire is bundled with an orange wire, that is used for the 12 v feed to the trailer connector. You can find the end of these wires taped up in a bundle under the brake booster under the hood. Follow the brake lines down from the booster, almost to where they turn to head under the vehicle. The wires are probably covered with a decade of grease and road debris, so they might be challenging to find, but they ARE there.
reply by: Mike
Question:
I have a 2007 E-150 ford full size van and need to install a 7 way plug and brake controller to pull my camper.Will part # 118242 fit my van ? I had a 99 f-150 and bought a simular part from the dealer for that truck, but they say its not available for the van. thanks for the help
asked by: Steve last update: September 27, 2008
Reply:
I'm sorry, the 118242 will not work with your vehicle. Does your Ford Van have any kind of existing trailer connector?
reply by: Mike
Question:
we have a Coleman Tacoma tent trailer...until yesterday, we were towing it with a 2004 Tundra - we had a Voyager braking control installed on the Truck under the dash...we traded in the Tundra for a newer 2007 Tundra Limited with a bigger engine- the dealer said we didnt really need the Voyager thing put in - do we?
asked by: Paul last update: September 27, 2008
Reply:
If the trailer has electric brakes, and you'd like them to work, you'll need a brake controller. I'd go the safer route and install the controller. You'll also have less wear and tear on your truck's braking system.
reply by: Mike
Question:
Can you shoot me a diagram to wire up a 2001 dodge 3500 with existing 7way harness please? Vehicle socket that is.
asked by: Justin last update: September 27, 2008
Reply:
I'm going to guess you are wanting to install a brake controller on your truck. You say that the truck is already equipped with the 7 way connector? If this is the case, all you'll need is the brake controller wiring adapter. One end of the harness would plug into the port under the dash of your vehicle, and the other end terminates in 4 bare leads, which would connect to your brake controller. The port is located under the dash, to the left of the steering column taped to another harness near the emergency brake pedal.
reply by: Mike
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