Troubleshooting Trailer Wiring That All Turns Off when Brake Lights Come On
Question:
Ive used a power probe to test all my sources right, left, park, brakes and ground. When both brake wires are disconnected everything is fine. As soon as I throw power to a brake the lights go off. I take power away, wait two minutes and the lights comes on. Ive checked both leads to the brakes, neither one are grounded to the body. Im thinking of separating the grounds. Grounding the lights to the plug and the brakes to the body right now their all tied together. I have led park lamps, led brake lights, and incandescent park bulbs. Ive wired a whole house , this should not be this hard.
asked by: John R
Expert Reply:
When we normally see trailer wiring that all shuts off when a higher drawing circuit is activated it's almost always an insufficient ground not being able to handle the amperage draw of everything. The easiest solution is to run a ground wire from each light back to the main ground wire of the connector and/or improve the ground connection of the connector. Sometimes it's from overdrawing too but normally that will blow a fuse.
