View Single Post
Old 10-23-2017, 11:21 PM   #1
AF Newbie
Join Date: Jan 2014
Location: Los Angeles, California
Posts: 7
Thanks: 0
Thanked 0 Times in 0 Posts
Help with trailer wiring: It works when first wired-up, then stops working

I'm having trouble wiring up the lights on a trailer. I have a 4-way connector, and I believe I've wired it up correctly:

- White to the trailer frame
- Brown to the tail lights
- Yellow to the left turn signal
- Green to the right turn signal

I verified this wiring against the instructions at Unfortunately, it doesn't work. The tail lights, left turn signal, and right turn signal work when I first wire them up, but not afterward.

To elaborate: If I turn on the left turn signal on the car, then connect the yellow wire, the left turn signal on the trailer works fine, but only until I turn off the turn signal at the car. After that, the left turn signal on the trailer is unresponsive when I turn the turn signal back on. The same is true of the right turn signal and the tail lights -- they work as expected when I first wire them up, but stop working as soon as I turn off the turn signal or lights.

In all cases, I can disconnect the wires and reconnect them exactly as before, and the lamp in question will work properly again... until I turn it off and try to turn it back on. This tells me I haven't burned out a bulb or a fuse. At all times, the car's tail lights and turn signals work exactly as they are supposed to.

I am baffled by this. Does anyone have an explanation for why my trailer lights might work when first wired-up, but then stop working?

Some details: The car is a 1996 Nissan Pathfinder. The wiring harness on the car is an aftermarket T connector which I installed myself (see

T.C. is offline   Reply With Quote