Lights On Boat Trailer Do Not Come On When Lights On Ford F-150 Are Turned On

Question:

Ford F 150 already wired for trailer hook-up ... Turning indicators work on trailer along with truck Brake lights work on trailer along with truck Problem: regular tail lights do not work on trailer when truck head lights/tail lights are on ???

asked by: Ken

Expert Reply:

I would begin by checking the grounds on your trailer. You will want to make sure each light is grounded to a clean metal surface. The item you selected, Custer Trailer Light, part # TLK01, includes a plastic license plate bracket. Sometimes this can cause a bad ground connection for the tail lights. I would also check to make sure the vehicle side connector is grounded and to make sure the auxiliary fuse on your vehicle is not blown.

There is also the possibility that the vehicle wiring connector is overloaded and cannot support the amount of lights on your trailer. If you have quite a few lights on your trailer, this may be the case.

A wiring kit with high amp capacity would be the ZCI Circuit Protected Vehicle Wiring Harness, part # 119250KIT.

I have linked a video on troubleshooting ground wire and instructions for a similar harness.

expert reply by: Reno H