Diagnosing Trailer Wiring Problem When Horse Trailer Lights Work With One Vehicle, But Not Another
Question:
2007 Ford Explorer w/factory tow pkg, Brenderup Horse trailer 7 Pin round plugs on each No Trailer lights at all when pluged in The Explorer works with my 7 pin boat trailer The Brenderup works with my 7 pin Suburban Trouple shooting suggestions?
asked by: Eric D
Expert Reply:
Your most likely culprit would be the ground connection on the horse trailer. Make sure that the grounding point on the trailer is securely fastened, and is free of corrosion.
When this trailer is being used on the Suburban, it is probably getting a ground connection through the trailer ball. The boat trailer will work fine with the Explorer because it most likely uses a continuous ground circuit instead of using the trailer frame as a portion of the ground circuit.
Trying different vehicle/trailer combinations was a great way of trying to troubleshoot your issue. By doing so, you effectively eliminated both the trailer and the Explorer as being the problem. The grounding issue is pretty much the only remaining possibility.
