Troubleshooting Trailer Brake Controller on 2004 Chevrolet Silverado 1500

Updated 02/20/2017 | Published 02/18/2017

Question:

I have the activator controller. Installed on 2004 chevy Silverado 1500. Used the oem wiring harness. Wired black to black, red to red, white to white and blue from controller to light blue on oem harness. Did not use brown from harness. Plugged into panel under the dash second slot on the top from the left side. Installed 40 amp breaker in fuse box under the hood. Decimal on controller stays on all the time. Troubleshooting table says red wire is hooked to wrong side of stop switch. Not sure what I need to do to fix this problem. Thanks

asked by: Joe

Expert Reply:

I do have a possible solution for you, however the wire colors you mentioned coming from the OEM harness in your 2004 Chevrolet Silverado 1500 don't match up to the GM OEM harness I am familiar with. Typically the wires on a GM OEM harness are as follows:

Dark blue = brake out
Red = 12V power
Light blue = brake light switch
Black = ground

Since the colors don't seem to be the same on your harness, we can also try to connect the brake controller by using the wire locations on your harness. I have included an image of a wiring harness that should look similar to the OEM harness in your Silvardo with the exception of the wire colors. When connecting to the brake controller wires, ignore the color and just go by the location of each wire.

The wire on the bottom left of the harness is the ground and will connect to the white wire on the brake controller.

The wire on the bottom right of the harness is the brake wire and will be connected to the red wire on the brake controller.

The top left wire is the 12V power wire and will connect with the brake controller's black wire.

And finally, the top right wire from your OEM harness will connect with the blue wire on the brake controller.

Another option which may be easier is to use is the custom Plug-In Wiring Adapter from Tekonsha, part # 3015-P. One end of the harness will plug into the brake controller and the other end will plug into the port underneath your dash. I have included an installation video for you to check out.