<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">Originally posted by H3 Hummer:
Not sure if those are for the OEM trailer but if so, here is some information from another post.
From the GM wiring schematics for the H3, the dark blue wire goes from the bundle under the I/P to the rear bundle for the trailer brake.
So, you could tap into the red wire (B+ through a 30Amp Fuse) at the I/P bundle attach this to one side of the switch, then attach the dark blue wire to the other side of the switch.
The rear fogs you can then power off the dark blue wire. For a ground, just attach to somewhere on the rear bumper should be good enough. </div></BLOCKQUOTE>
That explaination was if you have the UY7 trailer package.
Back to the original question.
White: Ground (Can't get a dot on your tongue from this one, unless you grab hold of the battery B+ post

)
Brown: Park Lamps
Yellow: Left Rear Turn/Brake
Dark Green: Right Rear Turn/Brake