I have a 2010 G4500 cutaway. I need to install a trailer hitch. I am trying to figure out if the van is wired for a trailer. There are big bundles of wires by the rear bumper. What am I looking for? What would a 7 pin pre-wire look like?

 

I would think a 4500 would be prewired. there should be blunt cut wiring....ready to splice to the 7 pin connector. unravel the bundle and have a look for the 7 wires. the wiring loom used to have a tag on it indicating each wire in the bundle. there also should be a blunt cut under the dash for the brake controller connection or Some come with a gm connector pin that plugs into a fuse box. my truck came with a connector that you splice to the brake controller and plug into the fuse box under the dash.

look for these colours
brown park lamps
yellow left turn stop
dark green right turn stop
red white battery power
red black battery power
blue electric brakes
white ground