Half my Electrical is Down - Help

[Cmonster77]

While camping this weekend at the Oregon Coast, I lost power to an entire circuit on my 1977 Argosy 22.

While plugged into 120v, we came back after a day at the beach to find our water pump, various lights on the port side of the trailer and our Fantastic fan were not working, completely dead like a blown fuse. All other appliances and lights work.

I diagnosed by checking all fuses, flipping all breakers even though none were tripped and nothing came back on. I then disconnected the 120v plug to go back to 12v and nothing came on. I then checked the fuses up front for the trailer lights and inspected the fuse on the water pump and fantastic and everything checked out. I am at a loss of what to do next or if there is something I missed.

Also of concern was while plugged in we were at 13 volts on my meter and after unplugging I dropped to 10.7v in a quick time. I believe my batteries are in good order as they are new and I kept them well maintained over the winter. No issues before this weekend. Does this maybe indicate a short? Would a short drain batteries?

Please help.
Thanks,
Jim

[r carl]

It would be a good idea to get your batteries tested, at least you would know their condition.

[Melody Ranch]

Were any other 12 v circuits powered? It could be a ground for the one circuit you mentioned. If all 12v is out...your converter is at fault most likely. The 120v comes into that point and then converts to 12v. It then goes to the circuits you have. Each of those circuits has to have a ground...either at the appliance individually or a main/common.

[A W Warn]

Check the output at the converter. And, there may be a fuse mounted directly on the end of the converter. If the converter is ok, there may be a breaker or fuse in the 12v line from the converter before it attaches to the fuse box.

[Cmonster77]

I do have other 12v fixture operating so it does seem to be only one circuit affected. It sounds like I can rule out the converter? Does the 12v batteries go through the converter output also?

I did check the fuse on the converter, two blade fuses and the main fuse to the fuse box. All checked out. I also checked all the other fuses in the fuse box, all good.

I will focus on grounding issues.

So I know electrical is weird and unpredictable, but to loose a ground on a fixture days after travel, rather than during travel seems like odd timing. I am wondering in there could be something specific that could have shorted in the water pump or fan. Any common issues on these devices that could lead to this issue?

Thanks again for all the help.

[Aage]

I don't know how you are checking fuses, but remember that they can look good and be bad (blown).

Find a known good one and re-check your fusebox.

Also, do a careful close inspection of the fuse holders, if you are using the little glass fuses with metal caps on each end. Look for corrosion on the holders. Mine got so badly corroded they lost their tension and heated up like a son of a gun due to higher resistance.

[TG Twinkie]

The fuses on the converter only blow if you connect it with reverse polarity.
13 volts sounds like the converter is working. But the 10 volt reading says dead battery(s). You may not be charging the batteries. Look for a fuse on the negative side of the circuit. Most are mounted separately on the skin of the coach .
You may have a bad connection at the fuse holder, meaning where the wires are attached. You may have a blown fuse or a bad fuse holder.
Even if the fuse looks good. Put a new one in and see what happens.

[mayco]

I agree with Twinkie, check to see that the connections at your 12v circuit panel are all tight. Sounds to me like something has come loose. Check and tighten the screws on the clamp connectors at the panel.