Parking light fuse blowing

[andyfuson]

I have a 2004 chevy truck which has a seperate fuse under the hood for the trailer park/tail lamps. When my Airstream is connected to the truck, if I turn on the parking lights, it blows my fuse. I have another work trailer which I pull with the same truck, and it does not blow the fuse, so I assume the problem lies with the Airstream.

Any info on how I might track down this problem?

Thanks in advance,

Andy

[AYRSTRM2]

yep, Open up the 7-pin connector on your trailer, it should come apart with hex key and a screwdriver. You'll probably find the ground wire has come loose and is touching the running lights wire. Every time you energize the lamps the current goes to ground and pops the fuse. This is from experience and the helpful advice of forum regular pattersontoo.

Or your running light wire is grounding to the shell somewhere in the trailer.

Start with the 7-pin plug first. Would have saved my camping trip if I had checked it first myself.

[andyfuson]

Thanks for the tip John. I had time to look at the plug today, and there is no way of opening it. The wire harness goes into the frame of the tongue with no visible signs of wear.

I was wondering if one of the marker lights could be shorted, and if I should remove all of the bulbs and then try to plug it in to see if it still blows the fuse. I'm not sure how to get to the wiring inside the trailer walls, etc. to even begin the search for the problem.

Andy

[wahoonc]

Andy,
It could be a bad bulb in the tail lights too. I have had a problem where the vibration had caused the lead on the tips of the bulbs to kind of blend together and it was causing a short.

Aaron

[SilverRanger]

Originally Posted by andyfuson

I was wondering if one of the marker lights could be shorted, and if I should remove all of the bulbs and then try to plug it in to see if it still blows the fuse.

Andy

Andy,

I had a similar situation a while back. After I isolated the problem to the trailer, I checked every accessible wire I could find. Then I discovered one of my clearance lights was out. I changed the bulb, and it hasn't blown a fuse since. I hope it may be something that simple for you.

[jimmickle]

You might consider purchasing a short finder from your local auto parts store or J C Whitney. Not expensive and a handy tool for finding shorts.

[AYRSTRM2]

Originally Posted by andyfuson

Thanks for the tip John. I had time to look at the plug today, and there is no way of opening it. The wire harness goes into the frame of the tongue with no visible signs of wear.

I was wondering if one of the marker lights could be shorted, and if I should remove all of the bulbs and then try to plug it in to see if it still blows the fuse. I'm not sure how to get to the wiring inside the trailer walls, etc. to even begin the search for the problem.

Andy

My problem wasn't visible either. You're sure there is NO screw or allen or hex screw on your 7-pin plug? Perhaps it is a friction fit. That has to come apart some how for them to connect the wires to the connector spades.

There is a was to determine if the problem is with the plug besides opening it up. You go under the camper and open the access hatch that is where all of the wires break out from the cable coming from the hitch. Using a continuity tester, you can see if the wires coming back are grounded or not. If the green wire, from the front is continuous with the ground, it's the plug. However, from there back you will have a tougher time, then you need to remove all of the bulbs and check each lamp individually for grounding.

Also, unless it is some sort of bad bulb issue, taking out the lights won't show the problem. Your short is BEFORE a lamp, if it's inside the camper. All lamps are grounded on the negative side to complete the circuit.

[andyfuson]

Thanks for more info. Today I looked at the plug again, and I could not see any way of getting inside. I got a short detector and hooked it up to my truck. Then I proceeded to remove all of the the running lights including the tag light. The short was still there. I also removed the tail light units to make sure that I did not see a wire that had rubbed against the body. I will be heading out in the morning for a trip to Table Rock State Park in SC, so I hope I don't run into rain. I don't normally drive at night, but I also don't excpect things to be wrong with such a new trailer. If you think I can pull hard on the plug and separate it from the harness, I will try. Otherwise I will have to consider hauling it to a dealer, which I hate to do.Luckily my truck has a separate fuse for the trailer, so I am not blowing my truck lights.

Thanks again for trying to help me out.

Andy