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EVERYTHING Trailer Brake Controllers


Charter Member
SM 2003
Full Member
Jan 18, 2002
New Jersey - Exit 5
I removed the trailer brake controller from my previous vehicle, and I've looked over the brake controller harness currently residing in one of my saddle storage box. I've reviewed the owner's manual and it gives no instructions as to how to install it, only to tell me to see the dealer.

Has anybody here installed the harness and a brake controller? I saw in the console topic that someone had their controller stored there when not in use. I'm thinking this can't be that difficult. The hardest part is probably mounting the controller somewhere under the dash. Unfortunately, the Av has the emergency brake release lever in the place that I had the trailer brake controller attached in my previous vehicle.

I want to install this myself, because I don't want the dealer to do it, and the RV place probably hasn't had any experience with the Av since it is so new. Any guidance would be appreciated!
I installed mine two weeks ago. It is real easy. under the drivers dash is the plug for the wire. Just plug it in and connect the wiring to the brake controller. Need you documentation from the brake controller. The documentation from the harness is on the harness. One other note! you will have to insert a fuse in the engine compartment fuse box. I forgot the name but you will see it. Is says trailer or trbrake or something like that. I sounds harder than it is. It only took me 5 minutes or less. I mounted mine right on the lower dash just above the gas pedel right next to the console.
Thank you Mr. Bill! I appreciate the info and will attempt the project this weekend. Although the documentation on my brake controller is long gone, I did tag each wire before I disconnected it from my prior vehicle, so hopefully that will help.

I thought the plug under the dash was for the mechanic to plug in the computer to read codes. Is that located somewhere else?

Does your shin or foot ever hit the brake controller where you placed it above the gas pedal?

Hi mid,

I installed a brake controller a couple weeks ago - it was fairly straightforward - the wiring is exactly the same as a Suburban or Silverado.

Here's how to decode the labels on the accessory wiring harness:

1) "Fuse B+" (red, heavy gauge) = +12V (duh)

2) "Brk Gnd" (black, med gauge) = ground (duh)

3) "Brk Sig" (light blue, med gauge) = brake signal (goes +12V when the brake is depressed)

4) "Brk Out" (blue, heavy gauge) = output from controller to brake (i.e., makes the rear trailer hitch connector brake pin active)

5) "Illum" (brown, med gauge) is for faceplate lighting which dims with the instrument cluster lights - I don't need it on my controller.

Anyways, the other end of the connector on the harness plugs into the "convenience" block in the driver's foot well on the left side - it's covered by a black plastic cover with a hand-tightening plastic hex nut. Removing the cover, you can use the "map" on the back of the cover to find the right connector to snap into (IIRC, it's on the top row, second from the left side - but verify before plugging in).

The fuse goes in the underhood fusebox - at "STUD A" - the leftmost unused slot.

I've mounted mine on the right side, mirror image of the brake-release handle. I drilled into the colored part of the lower dash - which is still invisible unless you stick your head into the footwell. No problems hitting my shin here.

Finally, the harness has about three feet too much wire length to it, so I just clipped it to a more appropriate length.

Hope this helps,
I guess Iam better at doing it than explaining it.
This forum is fantastic! You guys just saved me a trip to the RV dealer and installation cost. Assuming, of course, that I can follow directions.........
On a similar note>

I have a trailer with surge brakes. Instead of the typical
4 wire harness of gnd, lb, rb, brk....I have on the boat
a 5 wire harness. The extra wire is a back-up light wire, which allows for the surge brakes to disconnect when the AV and boat in tow are going in reverse.

My '95 Tahoe had the extra wire taped up in the wire harness and all I had to do was go buy a 5 wire plug
and hook it up, which then mated to the boat fine.

Since, the plug that was in the center console is only a 4 wire...has anyone been to the dealer for a 5 wire plug
or done something else to incorporate that back-up light wire into their existing 4 wire plug?
I installed a brake controller a few months ago right after I bought my AV. Just as everyone else has mentioned, the process is a sinch. Just follow the directions that Bill and Ed mentioned and you'll be fine. I installed mine on the dash right in front of my right knee. You may want to install a switch so you can turn off the controller when not in use. It also helps when backing up the trailer.
Thanks to everyone's info, I installed the brake controller last weekend and everything works well. I even hooked up the wires with quick-connectors, so that I can remove the controller from the truck when I'm not towing. With the bench seat model, I can lay the controller under the dash between the two front seats on the carpeted floor area, secured with velcro. If that doesn't work for some reason, I can always mount it permanently.
:cool: Like most people who will tow with their truck, I have installed a controller for the electric brakes on my race car hauler. Car (94 Camaro) and trailer are likely around 5000 lbs. If you have opened your glove compartment, you know GM gave you part of the installation harness. The rest of it will come with the electronic controller. I bought a unit built by Tekonsha Towing Systems, of Tokonsha, MI. I purchased it locally from an RV dealer. Most units are the same shape. I have seen brake units mounted via a U-bracket under the dash. While functional, that looks ugly and half-done. On my OnStar equipped Avalanche, I removed the two blanking plates directly beneath the OnStar plate, modified the holder by removing the center divider, (Actually, I bought a new one and modified that one), and mounted the Brake Controller with the front just sticking out enough to use the mechanical actuator and the sliding controls. It looks much better than hung underneath, is easily reachable for the driver, and, with the wire routed underneath and plugged into the stock fuse box, is almost completely hidden. Trick! :cool:
First, can anyone point me to the previous discussion on how to wire these suckers up? I searched and couldn't find it. Thanks in advanced.

Second, what do you tow-ers recommend. I already know I want a proportional type (not timer). Is the self leveling Tekonsha really worth it? Or should I just go with one of the simplier ones? What features should I look for?

I'm plannign on hauling a travel trailer, probably about 75% of the towing rating of the 2500. I know I'll need an equalizing hitch. Will I need to replace the receiver with something beefier?

So many questions, so many experts to answer. :)

Thanks midlife! That's the install thread I was looking for. I figured out why I couldn't find the posting: user error (didn't set the max age properly).
I have the Tekonsha Prodigy. Much easier to use than the previous Tekonsha I owned. I bought the unit online along with it the wiring harness. For 8.50 I just plug the harness into the prodigy and the other into the box under the dash and that's it. I have a suggested mounting location for the unit. If you like I can take pictures to show you. The location is nice because the driver can see it easily and the mounting holes are already there. :)
Where did you purchase the controller and harness from online? ???

Would like to see pictures if not much trouble.

I second orboater's posting.

About the harness, didn't your AV come with the harness? My harness came bundled with the hitch wiring adapter plug. They even included the fuse for the engine compartment.
About the harness, didn't your AV come with the harness? ?My harness came bundled with the hitch wiring adapter plug. ?They even included the fuse for the engine compartment.Yes it does have the factory harness. Having one that is pre-made with both ends in place would be nice. Could minimize the underdash clutter without the wire splices.
They give you a harness but as you said It's nice to have both ends finished. Below is the link to the dealer that I purchased the controller and harness from. I'm very happy with the dealer's delivery of product. If I get home early enough tonight I'll take pictures and post.

Go to the page below and choose the controlloer you want. At the bottom of the page is the wiring harnesses. Choose the GM model for your Av.

Thanks for the site info - just ordered a Tekonsha Prodigy and harness. Free shipping and no tax - seems like a good deal.

I spent my summers during high school and collage installing hitches, wiring and brake controllers at my Dad's RV shop (years ago).

It will be interesting to see how the new all electronic controllers install and work (the brake controllers that I worked on all tapped into the tow vehicle's hydraulic line at the master cylinder). Thanks again...Jim
Here's the pics of my Tekonsha Prodigy installed. The Prodigy unit has the mountable pocket so that you can easily remove the unit during non use. The pocket has two holes in the top for mounting. The manual says to mount it with the provided screws, which means you have to put holes in the dash. Because the unit has to be level and I didn't want to put holes in my dash I looked all around underneath for a mounting location. I noticed under the dash to the right of the brake release and under the steering wheel column there were two holes in the metal dash frame. I matched the holes in the controller pocket with these two holes, and to my surprise they came as a close match. ;D
I went to the hardware store and purchased 2 nuts, bolts and washers similar in diameter to the supplied screws but I made the bolts longer so that they would be easy to reach. The two washers were for under the dash for the nuts, the heads of the bolts were fine.
The location is easy to reach, easy to view, easy to install and is level both vertically and horizontally. Installing the pocket with the nuts, bolts and purchased wiring harness took about 20 minutes.

http://home.cyburban.com/~jeff/Brake Ctrl Av/under3.JPG

http://home.cyburban.com/~jeff/Brake Ctrl Av/front3.JPG

http://home.cyburban.com/~jeff/Brake Ctrl Av/withctr3.JPG
Thanks for taking time for pictures and the post.
Should be easy enough to do after instructions and pics.
Problem need help, ( I also posted this in the problem area, I really need to solve this)

I was hooking up my electric brake controller, no problems, until I touched the cable leads to the metal brake arm. Total accident because I was just setting the cable down.

Here is the sequence of events:
Hooked up the Av Trailer Wire Harness
Trimmed the ends to match it to the Prodigy
I followed the directions on the Prodigy to match up the wires
Before making the final connections I made just twisted them
Hooked up the controller, all worked great
Unhooked the wires and measured to trim them
Trimmed the wires and mounted the brackets
I went to hook up the new wires trimmed that is when I bummed the hot lead on the brake pedal. It sparked.
I went to check to make sure the fuses were ok and they are fine
Went to hook up the controller and nothing no power.

I thought the controller somehow got fried, even though it was not hooked up so I went to exchange it, which they did, hooked up the new and nothing.

What do I do, I have tried everything, am I missing a fuse, I check inside the main fuse box, the one inside the driver door, had OnStar do a computer check, and nothing. Am I over looking something, could have the power block under the dash been damaged in any way?

Helppppppppppppp if you can.