Trailer Wiring Problem (HELP!)

[moparme]

Well I wish I knew also. My rt turn & stop trailer lts have been out all summer. I have read alot on here about it, but have not changed the FCM yet either.

I do know all the fuses are good though.



sorry Im no help, just thought I would add my 2 cents

 

[Belchos]

Since the starter of this thread needed an answer on Oct. 2. , I am throwing this out for general consideration. I had the exact same problem on my '92 and it turned out to be one of those cheap clamshell splicing devices that HH was referring to. I have gone through the truck and replaced every splice with a three-way. I have not checked my '04 re those devices (I guess I assumed they figured that one out a long time ago, but ... what's the old saying: "There's an *** in assume") but I will be under the '04 this morning.

 

[bigflatdaddy]

Thanks for the replies everyone. I ended up on a trip without the trailer lights on that side. It wasn't too bad as I was only driving during daylight hours. Since that time, I've been trying to disconnect the harness under the driver's side, right behind the wheel well. I was hoping to find a corroded connection, or perhaps a place where there is still power to that wire. Any thoughts on how to get this darn plug apart? I just can't get it disconnected... .

 

[TMutziger]

Hope this doesn't waste your time, but reading jelag's response reminded me of an issue I had many years ago, and I want to mention it. I used a test light with the sharp "poker" probe to trace tail light wires on a car I had several years ago. (I think I was working on 4-wire trailer lights at the time). Then a couple years later, I discovered the left side tail lights on the car didn't work. Troubleshooting, I eventually discovered that salt spray from the Central New York winters had apparently gotten into the little pin hole I made in the wire with my test probe, and over the course of a couple years, had corroded the wire for at least an inch or two in either direction from the pin hole. I ended up replacing sections of the wire I had previously probed- the copper inside had turned to green powder. If you live in a salt climate, you may want to tape up the little poker holes in the wire insulation. I wish you best of luck tracing whatever is the main issue with your truck- hope it's something simple.

I had the exact same problem with the electric trailer brake circuit. Power at the fuse, but dead at the plug. I finally found a section of wire corroded were it had been previously probed. Replaced it and it works great.

 

[Cattechcolt]

Ugh!

I think I am experiencing the same kind of problems, but just the left trailer flasher isn't working... you can hear it in the (PDC), but it sounds sick compared to the right flasher... can differentiate by pulling the respective fuses... So my question is CAN you disassemble the pdc and get it back together without destroying it? I know the flasher units are built into it, but they are moving contacts, and I may have a shot at repairing them IF I can get the case apart and back together... any one ever attempted it? New ones are back ordered nation-wide in the U. S. , so used would be my only other option... THANKS!