in2pro

I added the Tekonsha 90195 Prodigy P3 Trailer Brake Controller to my 07 Tahoe. Currently we tow a less than 2000lbs pop-up that doesn't have trailer brakes. I will be renting a larger trailer for an upcoming family camping trip and the rental does have trailer brakes so this gave me the perfect opportunity ( justification ) to purchase and install the controller as we see a larger travel trailer in our future anyway.

If your vehicle has the towing package but not the controller, all the wiring is already there and is neatly tucked away under the dash near the e-brake release, it took me a bit to find it, it was tucked away well.
Look for the white label and blunt cut wires that are taped off..

Locate the red wires under the hood that are taped up for brake controller power and the trailer 12v. You only need the trailer brake power for the brake controller, the other line is for charging your trailer's 12v battery while driving.
The two studs on the underhood fuse box will be the connection points, both wires will come with ring studs already installed.



What's in the box, everything you will need.

(On a side note, I added a relay to the power line for my trailer battery line so that when the vehicle is not on and running it is disconnected from the vehicle. I had an issue with the trailer battery going bad and the trucks security system perceived the voltage drop of the campers battery as a door being opened when the truck was locked, causing the security system to believe the truck was being entered without being properly unlocked. I was greeted with less than enthusiasm by the park ranger while we were at the fishing dock asking if that was my truck making all the racket... we honestly thought it was some other inconsiderate camper so we didn't give the constant on and off horn honking any real thought)





Factory trailer brake controller wiring located under dash near e-brake release

The install is very easy, the Tekonsha controller came with a wiring harness ready to be spliced it, it even included the splices for all the lines.
I chose a spot under the dash that I could easily reach and see with my right hand and still have some room to lean forward if I needed to fiddle with it while moving, it has a manual operation lever that you should be able to readily access while driving, putting it on the left side of the steering wheel may crowd you between the driver's door if you lean forward to access the controller and make it difficult to view it at the same time.
The underside of the dash had a near perfect spot to mount the bracket, I used double-sided tape to test fit prior to drilling holes.






AUX power studs in the underhood fuse box for trailering

Perfect mount location just left of the center console under dash.




Good clearance and easy viewing.




closer view. The kit did not include the wire loom, I added that for a clean factory look. Note my Range device for AFM deactivation



I found the clearance for foot movement to/from accelerator and to/from accelerator to brake pedal very acceptable. the clearance issue won't come from the controller itself but from the wire-harness, so you will need to keep it wire-tied up and out of the way.
The unit is meant to be removed when not needed, so it easily comes out of its clip and the wire harness can be unclipped and tucked away. The controller comes with a nifty storage pouch and easily fits into the glove box.



Clearance and view from drivers prospective




I pivot my heel from accelerator to brake pedal, so clearance for me was hot an issue.

Thanks to Tekonsha for the following information:
General Motors quit offering the plug in type connectors on the 2007 model full size
trucks and S.U.V.s with a factory tow package. The 2007 models have four blunt cut
wires under the left side of the instrument panel. These wires are located above your left
shin as you are seated in the driver’s seat.
The wires can be identified by a white label and the color of the wires.
The wire colors are:
(1) Red/Black wire,
(1) White wire,
(1)Light Blue/White wire and
(1) Dark Blue wire and possibly (1) Orange wire.
Connect the brake control to these wires as follows.
GM Wire to Brake Control Wire Function
Red/Black Black Battery Power
White White Ground
Light Blue/WhiteRed Brake Light Signal
Dark Blue Blue Brake Output to Trailer
Orange N/A (CHMSL)
There are two wires under the hood that have to be connected to make the tow package
functional, one is the power wire to the brake control and the other is the battery charge
line to the 7 way connector. These wires are both Red/Black with eyelets connected to
them. They are coiled up under the hood and will need to be connected to the under hood
fuse box. One of these wires can be found located between the fuse box and the left
(drivers) side fender. The other is located under the master cylinder/brake booster
assembly.
The battery charge wire and the brake control wire have different size eyelets on them
and will connect to the threaded studs under the Gray handle of the front of the fuse box.
The two studs are also different size.
Note: GM does not supply the nuts required to secure the wires to the studs. These can be
obtained locally.
Important: Raising the Gray handle more than 3/8 of an inch to gain access to the
studs, will result in the fuse box coming disconnected from the electrical connector.
If disconnection occurs you may have to see your local GM dealership for repairs.



Kodus to member SWPDX for the helpful description of where to find the wiring harnesses at this post brake-controllers

I will expand on that post here with some pictures..