Help!!! Fuse or wiring problem?

[pamelake]

I have a 1974 25’ Tradewind. I am packed for my ‘maiden voyage’ tomorrow and something strange has happened with the electrical system. When I turned off the light switch by the door that works the light over the sink, my middle overhead lights, the light over the bed, the light over the dresser, the light over the door, the control panel (including the power to the water pump) all went out. I tested all of the fuses and they appear to be good. They all light the 12-volt tester. Any ideas? Also, after running the rest of the lights and the refrigerator for a few hours, the fuses felt hot. Is that normal. I am distressed. Thanks for any thoughts. Pam

[john hd]

pam

if you have the original glass fuses in your univolt the contacts that hold them can become corroded.

try a light spray of wd 40 in the fuse block and then rotate the fuses in the holders. pulling them out and reinstalling them works best.

look for loose fuse holders when you do this, you can gently squeeze the holders together with a needle nose pliers to get a better grip on the fuses before you reinstall them.

hope this helps.

john

[smily]

I have seen fuse boards or the "plate" that the fuse holders are mounted to, become brittle with heat and age. The board can crack and you will not even know it because the "bus" or conductor strip is on the back of the board. This Bus supplies voltage to the line side (the input side) of all branch circuit fuse holders. It can break or seperate and the main voltage will not be applied to the fuse.

You metioned that there was voltage at all fuses. Provided that the board is in tact ,(opposite description above), are you testing the fuses on the load side (the output side of fuse)?

I suspect that you have lot ground between the batteries and the coach. Usually when a lot of things go out, it is ground problems.

Good luck,
Smily

[Over59]

PO make not have used the right size (amps) fuses when replacing.
When you turn the switch does everything then work again. Prehaps someone rewired it as a master switch to turn everything off. How many fuses are there, do you know what each one does.

[pamelake]

I didn't which side was the output side. I put the tester on each side and it lighted each time on every fuse...does that mean they are good???

Originally Posted by smily

I have seen fuse boards or the "plate" that the fuse holders are mounted to, become brittle with heat and age. The board can crack and you will not even know it because the "bus" or conductor strip is on the back of the board. This Bus supplies voltage to the line side (the input side) of all branch circuit fuse holders. It can break or seperate and the main voltage will not be applied to the fuse.

You metioned that there was voltage at all fuses. Provided that the board is in tact ,(opposite description above), are you testing the fuses on the load side (the output side of fuse)?

I suspect that you have lot ground between the batteries and the coach. Usually when a lot of things go out, it is ground problems.

Good luck,
Smily

[pamelake]

I have the service manual, but can't find a schematic that shows what fuse runs what. It does not work again when I replace the fuses...they appear to be good when I test them. Thanks. Any other thoughts?

Originally Posted by Over59

PO make not have used the right size (amps) fuses when replacing.
When you turn the switch does everything then work again. Prehaps someone rewired it as a master switch to turn everything off. How many fuses are there, do you know what each one does.

[Jim & Susan]

Originally Posted by pamelake

I have the service manual, but can't find a schematic that shows what fuse runs what. It does not work again when I replace the fuses...they appear to be good when I test them. Thanks. Any other thoughts?

Pam, I have a '73 Overlander with the original Univolt powering my D.C. stuff. If your '74 is like mine (and still using the Univolt), then the D.C. probably feeds out the front of the Univolt. Some of my fuses have multiple wires tied to a single fuse. It could be that an individual output (fuse) powers all of the wires leading to the specific devices that have stoped working properly. If this fuse is intact and you have power on the side of the circuit that feeds the lights, etc, then there must be a ground problem someplace.

If you can wait until this evening, I can trace some of these out in my trailer and provide a few pics and a better description. We are in the middle of a full remodel with the entire interior out and all wiring exposed. Maybe this will help. Good luck and congrats on the first trip! Jim

[stinkytwinky]

Remember to turn off the electricity before servicing or testing your Univolt, or any electrical devices for that matter. Unless testing requires that voltage be applied.



on a side note you should check your fixtures and see if power is getting to them. You should also check your control panel for a fuse behind it. I own an Argosy and I do not have anything similar to a control panel (just one more thing to break). Good luck on your project.