Wiring Trailer Brake Controller 2003 GMC Chevrolet From Earlier Models 1999 2000 2001
Having trouble with your trailer brake controller wiring swap from your older Chevy or GMC to your new truck? Like many people, I got a newer truck and thought that simply removing the trailer brake controller from my 2001 GMC Silverado and plugging it in to my 2003 Chevrolet Silverado would be that easy. Well it wasn’t that easy, but still pretty easy with the right information.
For some reason Chevrolet decided to swap just 2 wires on the trailer brake plug receptacle. In the 2003 and later GMC Sierra and Chevrolet Silverado models, GM swapped only two wires from the 1999, 2000, 2001 and 2002 GMC/Chevrolet Silverado truck wiring schematic. In my Draw Tite trailer brake controller it was the Light Blue and Brown. The Light Blue color wire was labeled A and the Brown wire was D. See photos, schematics and wiring charts for more detail and watch the YouTube video if you need more information on the wiring fix. You can either cut the A and D wires and splice A to D and D to A or you can simply swap the A and D wire at the wiring harness connection. You don't even have to reattach the wire A (Brown) if you only have a 4 wire break controller that doesn't require an illumination connection. This wire simply illuminates a display on certain controllers when he headlights are turned on. If you were removing a newer electric brake controller and installing in an earlier model Chevrolet or GMC then you will do the opposite wire switch.
Swapping trailer brake wiring at the harness connection is very simple and takes only a few minutes. The first thing you do is remove the blue clip or keeper as shown in the photo. An flathead, eyeglass screwdriver will be all you need for this wire swap. Then carefully push screwdriver between the wire harness plug tab and individual wire connector within the harness plug and pull wire back or or push out from the front end that you are working on. After you remove both wires, just push the (teal) wire that was in the A position into the D slot and the (brown) wire that was D into the A slot. I had the DrawTite brake controller with these wire colors, but they could be any color depending on brand or individual brake controller installation. My colors included a large RED wire, large Blue wire, teal, brown and black. You may have a white wire or a yellow wire in there so that is why we are talking about the letters in relation to wire position.
Do not attempt to perform and electrical repairs to your vehicle without disconnecting the batter first. If you are not 100 percent sure that your trailer brake controller will work using this method or you have another make vehicle, please seek help from an experienced technician. You may also want to use a voltmeter to double check the wiring by comparing both vehicles, but you will have to connect the battery. These instructions are based on removing a DrawTite Activator 2 from a 2001 GMC Sierra 2500 HD and modifying the wiring to work with a 2003 Chevrolet Silverado 2500 HD. Later model vehicles may not work with these instructions so consult a technician before attempting, to see if the wiring scheme is the same.
Visit http://YouTube.com/How2Auto for more on trailer brake control connections and wiring instructions for GMC and Chevrolet Trucks.
