Trailer Light Question

[stfnwuf]

Our 2010 Cougar or our 2009 RAM have begun something very perplexing. After approximately 10 minutes of use, the clearance/running lights on the trailer stop working. The brake lights work, the turn signals work, the brakes work, and the indicator on the brake controller confirms that we are hooked up and that the circuit is complete. I have tried disconnecting and reconnecting the lead and I have tried cleaning the connections. My first attempt at cleaning the connections appeared to work or at least that is what I assumed. I now think it was just busy work as it was done before I began to drive away. The lights going out has now occurred repeatedly in all weather conditions. When they are working, all of the lights are burning. Again to summarize...

I connect the lead and all the lights work.
After about ten minutes, the clearance lights (tail lights included) stop working.
The brakes still work.
The brake lights still work.
The turn signals still work.
The brake controller indicates all is well.

What the heck am I overlooking?

Signed
Currently Dimwitted

[stfnwuf]

Another update on the running lights. The truck was at the dealership getting new tires so we asked them to check out the running light issue. The dealership checked out the system and felt it could be the plug at the fifth wheel hitch that was added when we had it installed. They suggested we use the factory plug in at the hitch on the bumper. My husband didn't think that was the issue, but in order to say he tried everything, he agreed to do that. Well, same issue. So, it has to do with the module in the truck. At least the issue has been narrowed down.

[stfnwuf]

It took awhile, but my husband thinks he found the issue. It's the truck, not the trailer. He was able to plug a friend's trailer into our truck and the lights did not work. He is taking it to the dealership tomorrow. We will see what happens.

[trail-explorer]

Any luck figuring this out?

[stfnwuf]

Thank you, all. Passing this onto my husband who did the original post. Fixing this is his project for tomorrow he says. Will let you know what happens.

[handye9]

With battery installed and no shore power on the trailer, insert a 10 amp fuse between the slots of the umbilical cord, that are on both sides of the notch.

What this does is, supplies power to the running lights from the trailer battery. If they light up and operate normal, your problem is in the truck.

Your description really sounds like a poor connection between the umbilical and the truck plug. Maybe an intermittent ground problem, could even be a fuse issue.

If your truck is wired similar to a Ford, it has a fuse / relay (in fuse box under the hood), that is solely for trailer running lights. There is a seperate fuse / relay for brake / tail / turn lights. That is why you can have one set of lights working and the other one, not.

Check owners manual for fuse / relay locations on the truck.

[copeland343]

I had the same problem. Loose ground wire on the truck connector. It had enough ground to let the brake lights work only two of them. The running lights used more power and worked for a while and quit. It was the connector in the bed so I used the bumper connector. Bought and new connecter to put on did same thing. I traced the wiring down to a loose ground connection on the truck.

[Bedlam]

Turn on your running/parking lights and verify that 12VDC is coming out of your truck connector. You need to determine to if it is a tow vehicle or trailer issue before further troubleshooting.

[Cool_Canuck]

campigloo wrote:
Loose ground wire?

Each light has its own ground therefore would not be that. If it was the trailer ground, all the lights would be affected so I doubt that is the case.

[campigloo]

Loose ground wire?

[ScottG]

Cool Canuck wrote:
Don't know about Dodges but there might be a overload protector in the circuit. I doubt it.

There is the most insidious of over current protection in 2006 and newer Dodge products.
It's called a Totally Integrated Power Module (TIPM) and while it does shut power off to an overloaded circuit, there's no way for the user to reset it - one has to go to the dealer to get it reset.
Oh and the TIPM can only be reset 2 or 3 times before it's fried and must be replaced - for about a thousand bucks.

So if the lights are coming back on then it isn't shorted. You have an open or bad connection someplace.

[Cool_Canuck]

The controller only indicates the brake circuit is complete. Nothing to do with the clearance lights. I'd check for a poor contact at the plug. Don't know about Dodges but there might be a overload protector in the circuit. I doubt it.