Wiring ??? about trailer

[The Adam Blaster]

I recently lost the left turn signal on my trailer.
Brake lights work, right turn, but no left.
Is it the bulb or a wiring problem?

[Mechanos]

Does the tow vehicle have seperate (amber) turn signals? The trailer uses the same circuit for brake lights and turn signals, so if both brake lights on the trailer work, then the trailer wiring and the bulb are ok. If the tow vehicle has seperate turn signals and brake lights, then it's probably a wiring issue on the tow vehicle side of the trailer harness plug.

Also check all grounds and make sure they are good. A bad ground can do strange things to the operation of the lights....

[64Trvlr]

I recently lost the left turn signal on my trailer.
Brake lights work, right turn, but no left.
Is it the bulb or a wiring problem?

A little more info would help.
You have a left brake light but no left turn signal?
Or you have NO left brake and NO left signal?
If you have No brake and signal then check the bulb.
If you have a left brake light and have NO signal, check the plugs on the trailer and tow vehicle for a loose/missing wire.

[Benny]

2 guesses.

1. You are towing with an import truck, the wiring converter is shot. My dad has this problem right now.

2. You are towing with a newer Ford truck. The factory trailer wiring on the truck sucks. I have "tried" to work on 3 separated newer ford trucks with the same problem. Never did figure out the real problem.

[The Adam Blaster]

It's a little utility trailer from Costco, not a car hauler, and i'm using my XJ to tow it.

Both brake lights work, but the left turn signal does not.
Being a Chrysler, they have this monster plug adapter that is round and 7-pin that connects to the 4-pin harness that comes from the trailer.

On the trailer harness, there's brown, green, yellow and white wires.

[CSP]

It's a little utility trailer from Costco, not a car hauler, and i'm using my XJ to tow it.

So does the XJ have separate turn signals and brake lights?? You haven't answered that one. There's only one wire going to the brake/turn signal on the trailer and in the plugs, so it must be something in the tow vehicle.

[The Adam Blaster]

Turn signal on XJ is separate from brakes, and they both work fine.

[64Trvlr]

Both brake lights work, but the left turn signal does not.

If the brake lights work then the bulb is OK. Looks like you need to check the wiring at both of the plugs or make sure your adapter is working OK. Do you have a test light?

[The Adam Blaster]

If the brake lights work then the bulb is OK. Looks like you need to check the wiring at both of the plugs or make sure your adapter is working OK. Do you have a test light?


Yup, it's pretty old, but i think it still works. :D

[CSP]

Turn signal on XJ is separate from brakes, and they both work fine.

Then you either have a wiring issue or the adapter taking the separate feeds into one output is bad. Replacement adapters are very inexpensive.

[64Trvlr]

Yup, it's pretty old, but i think it still works. :D

Good, make sure it works then use it, find the problem and post up the results. :flipoff2:

[FYRMAN]

XJ has seperate tunr/brake lights. He's got a converter. It's shot.

Brake light and turn signal are the same wire, same bulb, same filiment. If you got brake light, you got turn signal, unless your tail light converter is bad.