rear brake lights and turn signals both come on when brake pedal is pressed.

Thumper17 · November 10, 2017

I do some side work for a horse farm and they have a 2006 Chevrolet C4500 (Kodiak) that is used to pull a horse trailer. The problem that I am having is that when you step on the Brake pedal, both of the rear directional also come on. The unit has multiple add on lights on the custom body as well as 2 separate trailer receptacles. I have been all over the body trying to find the problem and worked my way to where the wiring comes out of the cab and plugs into the body wiring and still have 3 pins powered up at this plug. Was just wondering if anyone else has run into this? At this point, I think I am down to either a multifunction switch or a BPCM.

no HD · November 11, 2017

Sometimes the factory set up for the chassis wiring going to the rear contains two separate wires for the turn signals. One is wired through the brake light switch and the turn and brake are on the same wire. This usually goes to the trailer plug. Then there will be another set of turn signal wires that are signals only. That's used for the rear of the truck with another separate light for the brake lights. The body company probably wasn't careful about hooking up the wiring and has something tied together causing your problem, possibly.