Troubleshooting All Trailer Lights that Blink with Turn Signals when Headlights are On

Published 09/15/2015

Question:

I rewired a 1980 camper for 7 blade to match my jeep and all lights worked fine. Then I bought a 1994 chevy g20 to pull it and wired it to match the 4 flat wiring on van. I did not use auxiliary, brakes, and power on 7 blade. So now when the headlights/clearance lights are on and I use a directional all the lights on camper blink. But when those lights arent on only the correct directional blinks. Need help thank you

asked by: Ted L

Expert Reply:

What you described sounds like a classic bad ground scenario. Basically anytime there is unexplainable trailer taillight functions it's due to an insufficient ground. Also, anytime the headlights cause trailer wiring to act funny it's almost always a bad ground as well.

Make sure that the trailer side connector are clean and free of corrosion inside and out. The main connector grounds should be attached to clean and corrosion free bare metal surfaces. The light grounds should also be attached to clean and corrosion free bare metal surfaces. If there is anything between a light ground and the metal trailer frame or if the trailer has an aluminum frame, tilt bed, or folding tongue, any of these things can interrupt the ground. Running jumper wires from the light grounds to the main trailer connector ground can help.

expert reply by: Jameson C