Troubleshooting Electric Trailer Jack That Does Not Function

Question:

I hooked trailer to truck and in a hurry just plugged trailer cord to truck to raise lift jack on trailer without a battery. It worked. When I was ready to unhook trailer the jack would not work. For a second the hot battery wire touched metal and it sparked. I checked all fuses under truck hood that pretain to trailer and none are blown. Cant find problem. Can you suggest me checkng something else.

asked by: Joe

Expert Reply:

If all fuses/circuit breakers in your truck are good and the trailer's jack wiring is too, the first thing I would check is the power switch on the jack. If you can access the jack motor terminals directly and apply 12V power direct from a battery, bypassing the switch, then you will be able to determine if the switch was damaged when you experienced the short. If the motor works when directly powered then you know the switch needs to be replaced. If the motor does not respond to direct power input then it may have been damaged, or there may be an internal fuse or breaker inside the jack that has blown.

You can also inspect the truck wiring to see if the power draw from the jack damaged the 7-way wiring or connector in any way.

I linked out main pages for electric jack replacement switches and motors.

expert reply by: Adam R