Are Ground Wires the Cause of Both Turn Signals on Trailer Blinking

Question:

All the lights on my trailer work properly. Running lights come on, brake lights work on both sides, turn signals work properly. The issue I have is when I hit the brakes while either turn signal is on. Hitting the brakes causes both signals to blink. All grounds are clean and tight. I’m baffled.

asked by: Mark

Expert Reply:

The issue is a bad ground somewhere, though I understand you said they are "clean and tight." There is no other logical explanation for what is occurring so what you will want to do is check the ground on your vehicle harness as the leading potential cause for this problem. Also make sure the wires on your connector are fully seated, and I very highly recommend using Dielectric Grease for Electrical Connectors # 11755 to help prevent any type of corrosion in your connector; using it will increase your connector's durability and extend its lifespan.

I have added links to a pair of help articles on trailer wiring, including a troubleshooting guide which I highly recommend taking a look at.

expert reply by: Kyle S