Where does the factory HD Trailering Equip Harness go? (1999 K1500 Suburban)

[mackguy]

Our new Suburban has the HD Trailering Equipment (VR4+Z82). A PO somewhere along the line hooked up a permanent 7 pin connector next to the hitch.

The owners manual tells you how to wire up the 7 pin connector at the hitch end, but doesn't seem to say anything about how to hook up to a brake controller at the other end. I don't see any provision for a previously mounted brake controller, though I haven't looked super hard.

How do I get that set up?

 

[skylark]

The wires are factory taped together. If I recall they are blue and orange. You will find them right by the brake booster. At the back they will be tucked inside the left frame rail by the bumper brackets.

 

[grampadirt]

I believe any newly purchased brake controller will have wiring instructions.However,to expand on what Skylark noted,IIRC the blue wire is for signaling the trailer brakes and will connect to the controller.The red/orange wire should have an ''eye'' on it and should be attached to one of the studs on the outside of the fuse block(will be hot at all times).That wire when attached to the 7pin plug will charge the trailer battery(if equipped).

 

[eluwak]

I used this video to install my Tekonsha P2. I also had a 7 pin installed by the PO, but they didn't hookup the power or brake wires. The biggest pain was drilling the hole through the firewall to fit a small grommet.

https://www.etrailer.com/tv-install-brake-controller-1999-chevrolet-suburban-5500.aspx

 

[mackguy]

Thanks I will check the video at some later point, but mostly was looking for where the wires should be. Just thought it was strange the manual told you how to wire the 7 pin connector at the rear, but no indication of what to do up front. This is really helpful!

 

[BoxerPitMix]

Those wires on the firewall can sometimes be a real pain to find. I've found them right near the brake booster at times - and other times I had to crawl under the truck and dig in the harness. Then there has been several occasions that there just wasn't any there when it was supposed to be equipped with them. The blue you'll find in the harness next to the spare on the inside of the frame IIRC (though if you have a 7-way plug, it's probably already there) along with the orange.
I know starting on NBS trucks there is a fuse in the underhood fuse box for the orange charge wire, but I honestly can't remember on these.

What year is your suburban?
It's been several years since I installed one on a GMT400, but I believe the easiest place to catch the stop light wire (red wire on your brake controller) is by just running it to the right terminal of the NAT empty plug in the junction box behind your parking brake.
Then of course there's white (ground - we usually just ground those to the dash frame with a self tapping screw), blue (brake), and black that needs to run to a fused/breaker +, I just run it to the same post as the charge wire under the hood on the fuse box.

 

[mackguy]

It's a 99 so should be the same as your Yukon (which looks real nice btw!).