Turning Light Circuit Breaker Blows

[flrp]

I recently purchased a new 5th wheel and got along find with the electrical system on several trips. Each time I connect the 5er to the pickup I check to make sure the brake and turning lights work on the 5W. Then last week after hooking up the 5W to the pickup I was checked the turning lights on the 5er and the left turning light wasn't working, the brake and running lights worked find. I checked the corresponding circuit breaker on the pickup and sure enough the the 10A fuse was blown. I installed a new 10A fuse checked the turning lights on the 5er and they were working properly. Now the question I have is what caused the 10A fuse to blow? I am the kind of person who wants to know if something fails what cause it. So does anyone have suggestions as to what may have caused the failure. Is there a wiring problem on the 5W I need to check out?

[YC_1]

No reason, just policy. Fuses die of natural causes all the time. Of course keep checking the lights and do a very thorough inspection of the plugs, sockets, and any wiring you can follow looking for chafes.

I have replaced thousands of fuses in 40 years with no apparent faults. Working in the 12 volt world with many other technicians this is common.

[Jpony56hd]

It would be a good thing to check the bulbs and sockets for corrosion. This is common and drives service technicians crazy, it will work once and fail the next time. It's usually between the body of the bulb and the socket, interrupting the ground path, causing the circuit to search for another ground path, overheating the circuit, blowing fuses and breakers.

[donn0128]

Possibly a short when you plugged in, or simply a fluke. Have that happen to me once or twice, then fine for years.