Troubleshooting Reese Brakeman IV Electric Brake Controller

Published 08/28/2018

Question:

Reese Brakeman IV I recently installed electric brakes on my atv trailer and the brakes are minimally on all the time causing them to heat up. I used a friends pickup and the brakes worked well, no heating up. We checked my 2017 Silverado and found that there is 0.136 volts on the blue wire, normal 14 volts on the black, and zero on the red and white. Should there be any power to the blue as that wire seems to come from the brake light switch at the brake pedal?

asked by: Kent A

Helpful Expert Reply:

There should be a minimal amperage draw on the 5 o'clock pin of your 7-way from your trailer showing the brake controller that there is a trailer connected. That should not give you enough power to apply your trailer brakes and cause any issue. The white wire is ground and should have no power, the red wire should only have power when you hit the brake pedal, and the blue output wire should only have that small draw and nothing when the trailer isn't connected. The black wire should have the 12V power which will be slightly higher with your alternator. I recommend cleaning the connector with some sand paper to ensure you don't have corrosion causing power draw from another function on your brakes.

I've attached an article to assist with testing your brake controller as it sounds like it may be sending constant power. If this is the case, I recommend replacing it with the Prodigy P3 # 90195 which will allow you to use the same wiring harness if you determine the wiring isn't an issue.

expert reply by: Jason S