Wiring for under dash trailer brake controller

[corvettetim]

Hello group, I have a few questions about aftermarket under dash controller for my 07 Yukon Denali. I'm reading the owner's manual about hooking up the wires. First it states that you have to connect the striped red/black under the dash to the under hood electrical center, I found the wire, unwrapped it now where does it connect to ? Looks like it could connect to a battery but I don't have 2 batteries. Can I just hook it to a hot feed somewhere ? Second it states there are "blunt cut wires near the data link" that are for the wire connections for the controller. Anyone know where they are ? I was looking under the dash for about 1/2 hour chasing wires and could not find any harness that contained the right color wires. Any help would be appreciated very much. TIA

 

[swathdiver]

The under dash wires are taped up close to the parking brake release. Fives wires looped together. There's a white sticker on it which labels the wires.

Under the hood between the fuse box and the fender is the other wire and this connects to the left hand stud on the electrical box (pull the cover) with an M8 nut.

If you want your truck to power the inside of the trailer, the taped wire under the brake booster attaches to the right hand stud with an M6 nut. The fuse for it should already be installed and remember, that as long as the trailer is connected, your battery will power whatever is on inside, including the trailer's battery.

 

[corvettetim]

The under dash wires are taped up close to the parking brake release. Fives wires looped together. There's a white sticker on it which labels the wires.

Under the hood between the fuse box and the fender is the other wire and this connects to the left hand stud on the electrical box (pull the cover) with an M8 nut.

If you want your truck to power the inside of the trailer, the taped wire under the brake booster attaches to the right hand stud with an M6 nut. The fuse for it should already be installed and remember, that as long as the trailer is connected, your battery will power whatever is on inside, including the trailer's battery.

Thank you for that info, you are way more helpful than the damn owner's manual. Tomorrow I will be hunting for the wires under the dash and now know where to connect the under hood wire. I am going to be pulling a flat bed car trailer so the left stud is the one. One question though, are those studs only hot when the key is on ?Thanks for the help.

 

[Fless]

Watch this install video; it covers the underhood connection, too:

https://www.etrailer.com/tv-install-brake-controller-2008-chevrolet-tahoe-90885.aspx

 

[swathdiver]

One question though, are those studs only hot when the key is on ?Thanks for the help.

Not sure about the left one, the right one is hot and transferring power all the time unless the fuse is pulled.

 

[Fless]

The brake controller circuit should be powered at all times, and I would wager that both of those circuits are powered at all times. When you're towing, and you stop for a long break, you might want to disconnect the trailer connector if you're sending aux power (not brake power) to the trailer. That can drain your battery if left connected long enough.

 

[Geotrash]

The brake controller circuit should be powered at all times, and I would wager that both of those circuits are powered at all times. When you're towing, and you stop for a long break, you might want to disconnect the trailer connector if you're sending aux power (not brake power) to the trailer. That can drain your battery if left connected long enough.

Yup, it is. In addition, I believe that the BCU will monitor the power usage on that circuit and shut off the trailer aux power circuit to limit battery drain.

 

[corvettetim]

I appreciate all the info I got here, you guys are the best. Got it all hooked up and everything checks out in the garage so tomorrow I will hook the car trailer to the Denali and see how it works. Thanks again.

 

[corvettetim]

Thanks again, everything works great .