Troubleshooting a Short Circuited Curt T-Connector Vehicle Wiring Harness on a 2006 Ford Freestar

Question:

2006 ford freestar: my lights are not working. I found the 10v fuse blown. I have used them before and they worked fine. I have also found the transformer I put in spare tire compartment is very hot. i found even when the vehicle lights off and the left turn signal on a constant light on the passenger side light on the trailer is on. Is the transformer possibly burnt up?

asked by: terry h

Expert Reply:

It sounds as if there has been a short in the system at some point. There are many situations that could cause this, but the important thing is that the converter and inline fuse have protected the sensitive circuitry in your vehicle from a potentially damaging situation. I checked our catalog and the recommendation for your vehicle is to either use this T-Connector style plug-in harness or see the Ford dealer for trailer wiring. Splicing a trailer wiring harness is not recommended. Your best option at this point is to replace the Curt T-Connector Vehicle Wiring Harness, item # C56673.

Before installing a new trailer wiring harness and plugging in your trailer, test the wiring harness to be sure it is functioning properly. You should make sure that there are not any conditions on the trailer that caused the original harness to malfunction before plugging in the new harness. Make sure all of the trailer lighting ground points are securely connected to clean, paint, rust and corrosion free areas on the trailer frame and that there are no pinched, cut or frayed wires that could cause a short circuit situation. Also, when plugging in the new harness be careful not to bend any of the pins inside the connectors. If the pins are bent during installation a short circuit can occur.

The original wiring harness needs to be removed if the converter box is getting hot.

expert reply by: Robert G