Fuse that keeps flipping

[joelschneide]

Hello, I have a 1998 Airstream Excella 31'. I have been living in it full time for a few weeks now and just today I lost 12v power in the bedroom. The two furthest rearward overhead lights and the reading lights are no longer working (everything else in the trailer works). After looking at the 12v fuse box one of the fuses tripped. I pushed in the manual reset button on the side but it keeps tripping immediately. I used a voltage tester to confirm that the tripped fuse was not letting voltage pass through. I was curious if anyone else had experienced this or had any ideas? My fear is the chance of a random short somewhere in a wire that is causing the this issue but thought I would pose the question to the forum before I start hunting down what might not be a short.

[Inestein]

During a search for blown fuses I found your thread. I have a fuse that keeps blowing and I have narrowed it down to the shower light. The switch tests good. The led light works in other fixtures without blowing the fuse. So I am down to the wire to the light I think....I am in a pickle about where to go next. I have just removed one lead from the switch for the moment and taped it up. It is on the same circuit as the bedroom cabinet lighting over the bed. Also the bathroom light but those work fine and the fuse blows when I turn on the shower light.
Dang....hope someone else has similar issues. I am still searching the forums for answers.

[Al and Missy]

Did this work once?
Did you try the switch with the LED removed? Does it still blow the fuse (Actually a circuit breaker).
Which wire did you disconnect, the wire to the light or the wire to the fuses?
If the wire to the light, turn on the switch. If the fuse blows the problem is in the switch.
If you disconnect the fuse panel wire, reconnect it, disconnect the wire to the light, and try the above test.

If the problem is not in the switch, pull the light fixture and look for problems there. Disconnect the fixture and try the switch test again.

[Inestein]

[QUOTE=Al and Missy;2402562]Did this work once?
Did you try the switch with the LED removed? Does it still blow the fuse (Actually a circuit breaker).

I did pull the LED from the fixture and tested it in the lamp with no issues.

I pulled the top wire from the switch at the shower and I can keep the other lights in use. That fuse also covers the bathroom light and reading lights in the bedroom. Also the overhead storage in bedroom. It is a 15amp blade fuse on the 12v side. Position number 1

I pulled the fan shroud in the shower to look at the wiring. The dealer replaced that fan for me when I bought it last year as it was not working but it looks like they were not very careful and screwed it in pretty much near the harness. I can't tell if it went into the harness but it was nicked a bit.
I also pulled the panel to access the harness from under the closet next to the shower and I still need to check wiring for trouble coming from lower harness to the switch.

[Inestein]

After pulling a new wire from the switch to the shower light I postponed my attempt and did not use the wire I pulled as everything was working fine again.

Again it just failed and blew the fuse on number 1 and I found that it also runs the A/C. So I am back at it with stuff pulled apart.

I am going to try that other suggestion of using my meter with an extension to the negative terminal, the fuse removed, and checking the positives until I find it. I am expecting to find a bad wire to that switch but I could be wrong. If I don't use the shower switch then everything else works ok.
I will try to remember to post my findings.

[ROBERT CROSS]

Fuse or breaker? Breakers do poop out too.

Bob
🇺🇸

[Inestein]

It was not the breaker but the first 15amp fuse. I did use testing and examined all the wiring. I could not duplicate and when I check dc volts I get 13v with switch on and 0v at off. I am not blowing the fuse now so I am guessing that is is a worn wire insulation that I can't see. I pulled a new wire to insert from the lower wiring loom harnesss behind the shower (switch area to the light) But at the moment is it just waiting there in the event I need to bypass the factory wire to the light.
I will wait to see if it blows again.