Troubleshooting No Power to Brakes on Trailer

Updated 09/28/2022 | Published 09/25/2022

Products Featured in This Question

Hook Probe Circuit Tester

(64)

$13.35

10 Gauge Wire - Blue Primary - Per Foot

(107)

$1.65

Pollak Black Plastic, 7-Pole, RV-Style Trailer Connector - Trailer End

(709)

$7.20

Question:

Hello. For some reason I am not getting any volt reading on the trailer side for my trailer brakes. The blue wire. When I test my brake post on my 7 way plug on my truck, I get good volts. But when I plug in my trailer and test the blue wire, I don’t get any volts. Please help. Thank you.

asked by: Cody

Expert Reply:

Since you already tested your vehicle and it sounds like it checks out, the problem must be on the trailer side. I'm not sure where you tested the blue wire on your trailer so we will start there.

Using a circuit tester like the # PTW2993, check the brake output wire right after your 7-way connector. If you have power here then there is likely a short somewhere in the wiring. If you can't find and repair the short you could run new wire using # 10-1-1.

If there is no power immediately after the connector, it is a problem with your trailer connector. Check for any debris or corrosion and clean as needed. If this is not present, or there is visible damage, I would replace it with the # PK12706.

expert reply by: Robin H