electric brake controller plug

[doghouse]

Does anyone know where the electric brake controller plug is in the tahoe's?

TIA
JR

 

[wedtwuk]

Electric Trailer Controller

I'm not exactly sure where this is located but here is the contents of a post that I found on another forum. Hope it helps.

Just finished install of my Brake Control on the new Chevrolet Tahoe.
Some prior Chev/GMC's used a pigtail and well labeled wires.
For 2007 the wires are looped under the dash.
I went to the Chev dealer and had a tech pull the trailer wire ends out from under the dash. I could see the wires but didnt want to take responsiblity - as the wires were bundled with a bunch of other wires. The tech also showed me the fuse box under the hood and a heavy duty red wire with a round connector. The red wire needs to be connected to a 30 or 40 amp fused auxillary terminal on the front end of the fuse box. New owner's manual not very helpful as instructions say to "contact dealer for installation".

The GM wires are marked:
Black/Red - Battery
White - Ground
Aux
CHMSL

Evidently the Aux is the Brakes and
the CHMSL is the Stoplights

 

[doghouse]

Yeah I figure I might be able to get the tech at the dealer to show me how to do it. It can't be that hard to do. If not there I was going to go to a trailer place and have them show me. I can mount it myself but just not sure where the plug goes in.

 

[kpanza]

I don't think there is a "plug" under the dash, just individual wires (the manual says "blunt cut" wires). So, I guess you just have to make connections to your brake controller? My brother's Suburban had a very convenient plug if I remember right, guess they don't anymore?

I saw two red/black stripe wires, pretty healthy gage, near the under hood fuse box...I assumed one was for Stud 66 or 71 (the ones they leave unconnected according to t he manual), but was not entirely sure which one to use. Anyone have any more info? There is supposed to be a Dark Blue wire in there also...

 

[genestoy]

Underneath the dash on the left side right behind or very near the connector that the tech's use to hook up their diagnostic tool is a taped bundle of four wires for the brake controller, a large red, large blue, small white and small blue that connect to your brake controller (some controllers don't use the small blue one). Under the hood between the fender and the fuse box are two red wires which fit on the terminal posts on the very front of the fuse box. The connectors on the ends of these two wires only fit on the correct posts and you will need metric nuts to secure them. One is for the trailer brake circuit (the 30 amp one) and the other is for the trailer charging circuit (the 40 amp one). Connecting up the 30 amp one will energize the red wire in the taped bundle under the dash so hook it up to your controller first.

 

[hyperlite91193]

Any other info?

Underneath the dash on the left side right behind or very near the connector that the tech's use to hook up their diagnostic tool is a taped bundle of four wires for the brake controller, a large red, large blue, small white and small blue that connect to your brake controller (some controllers don't use the small blue one). Under the hood between the fender and the fuse box are two red wires which fit on the terminal posts on the very front of the fuse box. The connectors on the ends of these two wires only fit on the correct posts and you will need metric nuts to secure them. One is for the trailer brake circuit (the 30 amp one) and the other is for the trailer charging circuit (the 40 amp one). Connecting up the 30 amp one will energize the red wire in the taped bundle under the dash so hook it up to your controller first.

Gene,
Your instructions seem pretty straightforward. More informative than the Dealer! The Dealer called GM headquarters and they offered no help on getting my Controller hooked up since they said the 07's are different and they aren't familiar with them yet! Yikes!

So according to your instructions, get the controller hooked up first, then deal with the connections under the hood later on... correct? I've never installed one, but I just purchased a TEKONSHA 90185 PRODIGY TRAILER BRAKE CONTROLLER. Any other suggestions or things I should look out for? Thanks!

Zach
07 Tahoe LTZ

 

[genestoy]

Zach,
Yes, I would mount the controller, connect all the wires (per the controller instructions) to the GM trailer harness wires I spoke of under the dash, tape and wire tie everything up nice and neat and then go to under the hood and connect those parts last. This way you won't have a hot wire loose under the dash while you are working on connecting the controller. When you are done use a 12v test light at the rear connector to check for proper connections/operation (you will need somebody stepping on the brake to activate the electric brake circuit). The picture below will help you showing which lug these circuits are on (the bottom left one is looking at your plug on the truck). Hope that helps.

If I am right looking at Prodigy install instructions--
From the controller--
Black goes to the trucks large red wire (the 12v hot)
Red goes to the trucks small blue wire (the stoplight switch)
White goes to the trucks white wire (ground)
Blue goes to the trucks large blue wire (trailer brakes)

 

[hyperlite91193]

Gene.... You are the Man! Thanks for the help! Hoping to install sometime this week. Thanks for the tips and pic!

 

[genestoy]

You are welcome! One other thing when testing the brake circuit at the rear the test bulb light will not be as bright as you are using reduced voltage thru the brake controller, so don't worry about that.

 

[hyperlite91193]

Thanks for the added info. BTW, the Chevy dealer in Thousand Oaks, CA should hire you!

 

[genestoy]

I worked for auto dealerships for almost 40 years in sales and am now retired. They do so little in the trailer dept as most rv dealers, hitch shops or somebody like U-Haul does these controller installations, so they don't really want to even mess with them. Good luck on your install

 

[hyperlite91193]

Help! - Wire Issue

Gene,
Thanks to your messages, I was ready to install tonight. But I ran into a snag!

First off, I found the four wires under the dash. That took quite awhile, but all looks good there. However, the two red wires under the hood have become an issue. I found them (what I thought was both) right where you said they would be… between the fender and the fuse box. When I unraveled the wire, I found that there was only one… not two!

I looked and looked, but there is only one wire coming out of the bundle, as shown in the picture below. Do you have any suggestions or insight on this?

 

[genestoy]

Zach,
The other wire could be taped on the other side towards the engine somewhere. Look around by the steering shaft or near the firewall even. There will be another bundle just like the one you found between the fusebox and the fender somewhere with the red wire and the two connectors will have different size holes in them so they only fit the right posts. Here is a pic of where that wire goes into the harness.

 

[hyperlite91193]

Gene,
Thanks for the reply. I will check it out tonight and I'll keep you posted. Also... thank you so much for your help thus far. I really appreciate the time and effort you've taken in helping me out!!!!!!

 

[genestoy]

No problem Zach, others have helped me and I don't mind helping when I "have been there and done that"

 

[kpanza]

The other red wire you need is below the brake master cylinder...taped up to a wiring loom just like the one between the fender and fuse box...the two red wires have different sized ring terminals, so there is no chance of mixing them up on the studs.

Go to the hardware store and get two nylock nuts to secure the ring terminals to the studs...I believe one was 8mm and the other was either 5 or 6 mm?? Sorry, my memory fails me right now...

 

[hyperlite91193]

Thanks for providing the location of the second red wire and nut sizes!

 

[kpanza]

Sure...I just took a few different sized loc nuts out to the truck to try (small hardware store, they trust me)...but I cannot remember which exact sizes I ended up with...I am almost certain the larger one was 8mm, and 6mm seems to be right...man, getting older sucks! ha,ha (32, going on 70 I swear!)

 

[mr dean]

Look between the circuit panel box and the brake lines coming from and under the master cylinder. That's where I found my other wire. Dean

 

[TARJr]

backup lamps on 2007 Tahoe

I can't seem to get the backup lamps (center pin of the 7-pin round plug) to work which disengages the disc brakes when I'm in reverse.
I've tried connecting the 2 red/black wires under the hood, and still no luck.