bing tracking image
Q & A Icon

Troubleshooting Possible Ground Problem on Boat Trailer Towed By 2008 Ford Escape


Ive got the curt wiring harness for a 2008 Ford Escape... It has been working fine for sometime. I hooked up my boat and the lights just wont come on for anything on the trailer. I turned off the head lights and the blinkers work but when I turn the lights back on they stop. Could it be the little box is faulty. Any help would be appreciated. I thanks.


Expert Reply:

My suspicion is that you have a poor ground connection somewhere on your trailer. The fact that everything works fine until the running lights are turned on is the dead giveaway. When the tail lights are turned on, the trailer lighting is drawing maximum amperage through the system. If there is a ground problem, this is when it will manifest itself.

There are several places to look for a poor ground connection. Lets start with the trailer connector on the vehicle. Trace the white wire coming off of the connector, and make sure it is securely grounded to the vehicle frame or chassis. Check that this connection is securely made to clean metal. Having the ground wire connect to metal that is corroded or covered with excessive undercoating will prevent a proper metal-to-metal connection. Next, move on the the connector on the trailer itself. Follow the ground wire and locate the point where it attaches to the trailer frame, which is usually on the trailer tongue. Make sure this connection is secure and not corroded.

Next, check the individual lamps. Each lamp will pick up its ground connection either through a separate ground wire connected to the trailer frame, or by its mounting bolts being in direct contact with the trailer frame. If a ground wire on each lamp is used, once again make sure its connection is tight and not corroded. If the ground connection is made through the mounting studs, make sure the mounting studs are in direct contact with the trailer frame. If the lamps are mounted to wood or plastic, you might have to run a short jumper wire from the mounting stud to the trailer frame.

A final possibility is the design of the trailer itself. Some boat trailers that feature a tilting or swinging trailer tongue can have ground problems. The trailer is actually two pieces, the majority of the trailer being one piece and the rest of the tongue and the coupler being the other. If the pivot between both parts of the becomes worn, the two halves of the trailer will not have consistent metal-to-metal contact, thus causing an insufficient ground connection. This problem can fixed by connecting the two portions of the trailer together with a jumper wire.

I'll link you to some troubleshooting help; an article that shows some strategies for diagnosing and repairing trailer wiring problems as well as a how-to video showing how to troubleshoot a taillight converter. I believe you have the ground problem, but you can troubleshoot the converter in order to rule it out.

expert reply by:
Mike L

Products Referenced in This Question

Product Page this Question was Asked From

Q & A Icon

Similar Expert Q&A Pages

See More Q&A Expert Answers >>