Does Brake Controller Have Constant Power

Question:

I have a 2005 Chevy 3500 with a duramax. It had a brake control box installed in it when I bought it but it didnt appear to work and looked like it was from the 1960s. I installed a new control box but the connector was different so I couldnt connect it. I decided to do some digging with my meter and the plug connected under the dash and I only have power between the red and white wires and only while applying the brakes. makes sense since the red wire is the stop wire. I think Im supposed to have constant power to the black wire correct? If so where does the power come from?

asked by: Kenny

Expert Reply:

A brake controller like the Tekonsha Voyager Trailer Brake Controller # 39510 will have constant power directly from the battery of your 2005 Chevy Silverado 3500, though the factory harness colors are different depending on the manufacturer. We have found that for your model year Chevy, with the factory wiring harness, oftentimes the red wire is the 12 volt power and a light blue wire is the stop light switch, which would only have power when you press on the brake pedals. The black would then be the ground and the blue would be the trailer brakes.

If you let me know what brake controller you purchased I may be able to get you the right connector.

I have also linked a help article on brake controllers which has the typical wiring colors for factory harnesses near the bottom of the article for you to take a look at.

expert reply by: Kyle S