No Power On Brake Light Circuit When Installing a Brake Controller

Published 04/07/2015

Question:

I found the green plug with the 4 wires, but there is no continuity from the green plug and the rv plug at the rear of the camper. Also there is no power at the green plug when the brake is activated with the key switch on. I do have 12volt power with the key on and a ground at the green plug. Is there a junction somewhere that may be unplugged? Or is the brake signal wire fused somewhere?

asked by: Gary

Expert Reply:

The brake signal should be fused. Check the vehicle owners manual for the fuse locations for the stop light switch or CHMSL (center high mount stop lamp). If either is blown there would be no power at the plug you found.

If you have a Chevy or GMC truck/SUV then it is also possible that there needs to be some connections made under the hood to make everything fully functional. I would need to know the year, make, and model of the vehicle to know if there are any peculiarities with your specific vehicle.

expert reply by: Michael H