lost the clearance lights

I think I'd unhook all battery power and use a multi-meter in resistance mode. I'm thinking that if you touch one probe to one of the positive connections (on your camper plug) and the other to the ground connection and it reads resistance then you have found the circuit where the short is. Try each positive one at a time and maybe you'll be able to narrow it down.

Disclaimer: As long as you don't have current flowing anywhere this can't hurt but I don't guarantee that it'll work either.

Blazing Zippers wrote:
I've wiggled and jiggled most everything--and no answer. Thanks all. Still looking for the short. The umbilical cord "seems" to be O.K. at the junction box, but now I'm going to cut the cord open and check if the short is further in the trailer.
Gonna need more beer.

I would start with checking the junction box first. Then like Scott G said and check where the wires go through the trailer skin if it is aluminum siding. There is a strong possibility that a wire nut has come off where it's attached to the clearance light or as Scott G suggested the wire may be shorted out. Usually the clearance lights are daisy chained one wire is run from the proceeding wire to the next light with wire nuts to connect them.

A remote possibility, but I've had this happen. Check the light bulbs (start with the tail lights) and ensure the elements hasn't broken and shorted out.

If you have clearance lights on a slide, check the junction boxes where the wires hook up on the slide. One may have come loose.

Other than that you may have to start disconnecting the lights one at a time to determine where the short is. It can be frustrating.

As a last resort, unhook from truck, jumper across from the battery terminal to the running light terminal (pin 4 to pin 3) in the umbilical plug and see where the smoke comes from. You can use a common fuse to do this. Use a high amperage fuse or a wire.

I've wiggled and jiggled most everything--and no answer. Thanks all. Still looking for the short. The umbilical cord "seems" to be O.K. at the junction box, but now I'm going to cut the cord open and check if the short is further in the trailer.
Gonna need more beer.

bucky wrote:
Wiggle the heck out of the 5er connection at the truck first. Gremlins can appear with the slightest bit of corrosion in the female receptacle.

Corrosion just causes the lights not to work, not blow the fuse. The OP has to have the wire grounded for the clearance lights. You'll have to trace the wire to find where it's grounded.

Wiggle the heck out of the 5er connection at the truck first. Gremlins can appear with the slightest bit of corrosion in the female receptacle.

One time I had the fuses popping for my clearance lights on our old TT.
When I got to the CG and checked the wiring I found that the manufacurer had used soemthing like an ice pick to make a jagged hole in the aluminum skin. Then they ran the wires through it.
It was only a matter of time.

I would trace the umbilical cord back into the trailer or junction box.

I'd take a look in the junction box, by the pinbox, that cord goes into. Sounds like a short from a loose wire.

Jerry