I think I know what is wrong, but I want to bounce it off the board and see how high it goes!

Last week my right tail light went dark, turn signal still worked. Popped the rear light off (and broke the lower push pin off - too cold). I changed bulb out, but still dark! Arghhh!

Tried to only drive in the sunshine, but that is difficult this time of year.

This weekend we were taking the Scouts out, so I had to used the trailer - trailer marker lights are all out, but the signals all worked properly.

What I'm thinking is that the connector where they tied the trailer tail lights into the truck wiring has come apart, taking the truck wire with it? It is an aftermarket wiring harness for the trailer wiring, so it doesn't tie in where it would if it was factory.

Thoughts? Too damned cold and too much snow to crawl under there this week, but will keep you posted.

 

Did you check the fuses? Depending on how well the trailer harness was attached, you could have a problem there that could cause the problem (short or open - a short would pop your fuse). I sympathize with your predicament & trying to find the fault in the cold, it's not much fun.

If you don't have the service manual downloaded from this forum, you might want to do that so that you have some detail on the wiring, fuses, connectors, etc., - for me, the Haynes manual is very inadequate in both detail and accuracy. A multimeter is almost a necessity for electrical diagnostics.

 

Sounds like a grounding issue... or that is typically the issue with a no trailer light issue and a partially lit bulb, but check your location first

 

Most Places that install Hitches use T-Connector Harnesses, So Usually they are not a issue, Same goes with most OEM aswell, Unless in our case I think the Factory Tow Package has its own wires to the fuse box, as they have there own relay for each side.
Check the ground on the Trailer Side of the wiring, It caused the lights on my Utility trail to not function, but Signals worked.

 

Thanks guys!

First thing I checked after the bulb was the fuses. They are fine. Both tail lights are fused together, so it has to be after the fuses.

Factory Tow package does have its own set of fuses, but mine is aftermarket and looks decidedly "Installed by Owner", so I doubt that it is with a nice clean packaged connector - but I'm willing to be proven wrong.

Maybe this weekend if the driveway melts enough and the temperature moderates a little I can get under and check it out.

Thanks again.

 

A lot of the DIY wiring efforts leave a lot to be desired. Wires just twisted together and sometimes covered with electrical tape (sometimes nothing) is prone to corrosion - the ground is often screwed up, if you don't have a multimeter available, you could try adding a good ground for the dead light and see how that works. The crimp-on butt connectors and splice connectors also corrode, giving either high resistance or an open circuit - this is where I find the answer to a lot of operational oddities.

 

Yes, that is my thinking. My multi-meter is at the ready! Just waiting on the weather and the time.

 

Snow is gone, sun was up yesterday, so I got under the truck and did some investigation.

I discovered that the original installer of the trailer harness had used the clip-on wire taps. Best access was behind the left side fender, so I jacked up the back end, put jack-stands under it and removed the left rear rim and tire.

Sure enough, one of the wires was disconnected at the clip - White with orange stripe which matches the wiring diagram for the right rear park lamp.

I wired up a harness with a side tap (soldered) for the trailer harness, with a pig-tail to span the area of the taps. I soldered all of them in and ran the harness back to the bumper. I tried the tail lights and the right side was back!

I was also less than impressed with the 7-wire harness plug stuck below the hitch - it is constantly getting damaged from snow banks and shrubs when I back into a parking spot.

A trip to Princess Auto yielded a new 7-wire/4-wire connector, now for where to mount it.

I like the "in-the-bumper" style, but our narrow step areas don't leave much room. I chose a spot to the left of the step and using a bimetal hole-saw, cut a 2" diameter hole in the bumper (after checking behind, of course).

Slipped the block in, drilled holes for the bolts and bolted everything down. I then soldered and heat-shrunk the wiring back there.

Using a trailer test plug I confirmed that everything works. Full test this Wednesday when I next connect to the trailer.

I still need a little paint and sealant to keep everything clean and dry.

 

Nice job. If I didn't know Dodges, I'd say that was factory.

 

The power of blurry photography!

Thanks!