1992 Chevy GMC 1500 Brake Controller Installation
"Standard" Wire Colors from Ford Trucks
When using a wiring harness supplied by your vehicle’s Manufacturer (OE Harness), DO NOT MATCH COLORS.
Please follow wiring chart below.
- Ford Wiring
- Brake Controller Wiring
- +12 Volts
- Ligth Green
- Stop Ligth
- Dark Blue
- Trailer Brakes
Remember, the above colors are just a GUIDE. your colors may be different, read the instructions!
We found the brake light switch tap on the switch. It was the white wire, second or third from the end (from the back of the truck) The picture shows looking up from the floorboard. Rather than reach all the way up to the switch, we un-wrapped part of the tap on the wire harness where it was easier to reach.
Get a test light and test all the pins on this plug, looking for the one that lights up when you press the brake pedal. The brake light switch is very hard to reach, so poking the wire might be easier, but with a probe tester, look for a wire under the dash that lights with the brake lights. You are probably looking for a small gauge white wire (seems most GM trucks of this era used white). Tap into the wire for the brake light feed (red wire on Tekonsha brand controllers)
For power, we ran a wire through the firewall, and tapped onto the fuse panel under the hood, through a 20 amp Fuse or Circuit Breaker.
We grounded the controller under the dash to a ground screw. Easy
The blue (brake wire to plug) was simply passed through a hole in the firewall and ran along the frame to the back plug on the truck. (making sure to use lots of tie wraps to keep the wire away from hot and moving parts)
UNDER THE HOOD:
We used one of the main power feed studs on the panel, and with a ring connector, got power to the Circuit breaker, to feed to controller. A 20 amp fuse would also work fine
We used a 20 amp fuse Circuit Breaker to power the brake controller, AND supply power to the 12 Volt power terminal on the trailer plug. This truck did not have wire ran to the back, so we used our 2 conductor brake wire and ran it ourselves. Drilled a small 3/8" hole in a rubber plug in the fire wall to run the wire to the brake controller under the dash.
From here, the blue wire from the brake controller is simply ran through the firewall from under the dash, down under the truck, to the Trailer plug at the back of the Van Make sure the wire is out of harms way when you run it to the back.