Trailer brake connection

This was discussed in this newsgroup in the last couple weeks. The wires were found on the OP's vehicle under the dash. Make sure that you actually have a 7 wire connector, by the way. Some GM & Chevy trucks came with a plastic do nothing blob that looks like a 7 wire connector, but instead had a different connector in the back of it, and they want you to buy an adaptor to their proprietary connector.

Bob La Londe

That was me on an 04. There are no wires, the "trailer brake harness" plugs into a box under the dash. Bought my harness on eBay, it is an original GM, came with the instructions and a 40 Amp fuse that goes in the under hood fuse panel. If your 09 has the heavy duty trailering package the connector should have been in the glove box.

Al

Nothing in the glove box, but I'll ask my sales guy.

Thanks.

No connector. There ARE 4 blunt cut wires accessable.

There are a red and a blue, look to be about 12 guage, and a blue and a black, maybe 16 or 18 guage. My wire sizes could be off, but should give an idea.

In the docs for my Odyssey controller, for Chev / GMC, it says red for 12v+, light blue for stop light, black for ground, and dark blue for trailer brakes.

Both blue wires are lighter blues. Do I have the right wires? Which blue is which? Anyone have access to factory schematics to check this?

FWIW, the connector on the bumper is fully wired. Looks to me like the larger blue wire is routed back there, and there is a smaller blue wire of the same colour and size on a switch on the brake pedal.

TIA

Man, this place is a wasteland recently.

So apparently the larger wire is what GM calls dark blue. I was able to obtain a wiring diagram for the rear connector, and the blue wire there was labeled as dark blue and it was the same colour as the one inside the cab.

The wires were the correct wires and the controller is now installed and working.