Ok i just recently bought i 1995 12valve, i went today to hook up the brake controller and noticed there was no harness, with further investigation i find that there is a wire ran all the way to the back of the truck but not hooked up to anything, and i also noticed that there is a splice already for the brake pedal that reads ground then hot. i just need to know where in the 7pin harness do i splice this wire. i have looked at the harness and saw a RED WIRE WAS SPLICED but have read i need to look for a BLUE WIRE.....IM GOING CRAZY What wire do i tap into on the 7 pin connector......it has a Factory trailer package
installed. IS THIS THE HARNESS IM LOOKING FOR

 

I have a 96 and there is a blue plug on the firewall behind the parking brake that is very hard to see. It is high on the firewall behind some other stuff and you can easily miss it if you do not look really hard for it.

This blue plug is for the trailer brakes.

I hope this helps...

 

thanks that gives me something to look for, any chance you could tell me the color wire coming out of it?

 

I can't get to it right now, I blew out my knee doing a triple reverse axle off the scaffold while remodeling the office and failed to stick the landing

Probably going to be at least another week before I am able to get down and crawl under the dash.