I have an '04 Chevy. It came with a hitch and 4 way plug. I added the brake controler, and hooked up the red line to the #2 stud and the bluw wire to the blue wire with supplied plugs in the fuse box. Now I need to wire a 7way plug in the back. The lights ect. are simple enough, because I just use the lines which were in the 4way plug. But which wire is for the trailer brakes? I would guess blue, but the left turn are quick-tapped into that line. Any suggestions? Thanks.

 

take a look in your owners manual they usually give you some guinence as to wire colors in the trailer towing section ,if your truck did not come with a factory hitch there might have been a 7 wire plug provision ther neer the spair tire with a dust cover pushed in it ,or not or a harness just taped up in the rear harness that will be label with a white tag .if the black plug with a dust cover is there yo7u can just plug a sealed 7 wire pluginto it made by drawtite #20012for the bracket 20015 for the plug