Troubleshooting No Power to Blue Output Wire for Brake Controller on 2012 Toyota Tundra

Question:

My trailer brake control does not work on my 2012 Toyota Tundra. It worked fine til now. I thought is was a bad unit, bought a new one and had same problem. I found a good ground under the dash , tested the black wire on the truck side of the connector and have power, tested the blue wire on the truck side of the connector while pressing the brake and no power. Is there a fuse or breaker somewhere. I have no idea.

asked by: Jim

Expert Reply:

It could be a fuse on your 2012 Toyota Tundra but I'm thinking that you either have a proportional controller like the P3 # 90195 or you aren't getting power from the cold side of your stop light switch when you press your brake pedal.

Most proportional controllers like the one mentioned above have an internal inertia sensor so if your vehicle isn't moving it won't send much power (if any) back to the trailer brakes because it can sense that you are sitting still. This helps to keep your trailer brakes from being applied when you are at stop lights and such.

Try using your tester, like part # PTW2992, to see what happens to the wire connected to the cold side of your stop light switch. This wire shouldn't show any power until you press your brake pedal on your Tundra. If none of your wires shows this then that means your brake controller doesn't know when your pedal is pressed which is why you aren't seeing power. This could be a fuse that needs to be replaced or you may need to install the Universal Stop Light Switch Kit # RM-751000 so that your brake controller acts normally.

I have also attached a link to a helpful article about brake controller troubleshooting for you to check out.

expert reply by: Jon G