Weird electrical problem

[theoldwizard1]

So I just fixed a very weird electrical problem on my daughter's family trailer. The only symptom I was originally given was the refrigerator does not work when switched to electric and there is no shore power.

Well, just as I was about to get started with my diagnostics, her husband said, "None of the lights work either !". Big clue, no power from the battery !!

So we checked the battery and it was good. No power to the 2 or 3 fuses we checked. Check the B+ wire in a couple of places underneath, GOOD ! So back to the converted/fuse panel. No obvious B+ without taking the whole fuse panel out. I studied the diagram on the cover and noticed that there was 40A fuse labeled "reverse battery protection". I pulled it out to get a good look and test with the meter. GOOD ! Plugged it back in and THE LIGHTS CAME ON !!!

[pianotuna]

Consider treating it with deoxit?

[afidel]

I'd recommend deoxit or similar to clean the contacts and then electrical/dielectric grease.

[theoldwizard1]

BobsYourUncle wrote:
Corroded fuse connection?
I've had fuses where I've had to clean up the contacts

Nothing obvious, but yes !

Removing and reinstalling the fuse actually makes tiny scratches.

[theoldwizard1]

enblethen wrote:
I would recommend getting a new fuse! Or at least carry one!

Well stocked on fuses !

[Lwiddis]

I agree with enblethen…new fuse and a spare plus clean the connectors.

[SAR_Tracker]

Just like an old carburetor. Take it apart, look at it, don't change anything, put it back together, and it works. PFM. Pure Friggin Magic!

[BobsYourUncle]

Corroded fuse connection?
I've had fuses where I've had to clean up the contacts

[enblethen]

I would recommend getting a new fuse! Or at least carry one!