Can Trailer Brake Output Circuit Wiring be Too Heavy

Question:

Would too heavy of wire cause trailer brakes not to work correctly if I put a test light at the plug on the back of the truck I have plenty of light when turned up and when I turn it down the light will dim but as soon as i hook up the trailer I have no brakes

asked by: Mark

Expert Reply:

Having heavier than needed wire gauge on your trailer's brake output circuit would not cause your brakes to not function. The problem you described sounds like a short on the brake output circuit of your trailer wiring or bad grounds on the brake assemblies. But first check to make sure there is not corrosion on the trailer's 7-way connector pins as that would easily prevent the brakes from functioning.

Inspect the wiring from the connector all the way back to the assemblies making sure there are no cuts or exposed wire and fix as necessary. Also make sure the assemblies are connected to a clean portion of the trailer frame. Running a jumper wire from the grounds to the main ground of the trailer would help as well.

expert reply by: Jameson C