Troubleshooting Brake Controller Weak Voltage Output at 7-Way Pin

Updated 08/12/2020 | Published 08/11/2020

Products Featured in This Question

Dexter Electric Trailer Brake Assembly - 10" - Right Hand - 3,500 lbs

(303)

$83.92

10 Gauge Wire - Blue Primary - Per Foot

(108)

$1.65

Question:

Hello, I have recently installed new trailer brakes on a single axle pop up trailer and they do not seem to be strong enough to stop trailer, even with gain maxed out. Brakes were adjusted correctly and tested while jacked up, at which point they seemed to be quite strong. Brake controller is a Tekonsha P3 and I have noticed through troubleshooting function of that particular controller that I am only getting 10v when manual slide is fully engaged. I have confirmed this by testing brake control output pin at rear of vehicle with multimeter. Could this be an issue with the controller itself, or is it perhaps a vehicle wiring issue? Any help would be much appreciated. Thanks

asked by: Sean B

Expert Reply:

You have definitely done a great job narrowing down the issue. Because you have adjusted the brake assemblies and tested the manual slider output at your 7-way, we know there is a voltage issue. This can be from a weak ground connection or a power output issue. I recommend testing the blue output wire from your P3 # 90195 about 6 inches from the back of the controller to determine if the controller output is the issue or if it is in the vehicle wiring. If you need to replace that wire you can simply run # 10-1-1 from the output to the 5 o'clock pin of your 7-way.

expert reply by: Jason S