Electrical troubles

[MountainTop]

We're on the road with our MPG 183 and have a 12 v electrical problem that baffles us. When not on shore power we can't get power from the batteries to the refrigerator or interior lights. When we started the trip everything was OK. Then the fridge wouldn't restart after a fuel stop (we turn it off before fueling). The Norcold fridge automatically searches for any available power source. When off shore power it doesn't pick up Dc power or propane as it is designed to do. That kicks off the propane alarm, as though there is no spark to ignite the fuel. For awhile we had interior lights when off shore power, but now those are out also. Have checked and rechecked fuses, battery terminals and battery water - all OK. Finally got an RV repairman to make a house call. His diagnosis was that our 2 batteries needed replacing, so we did that. Still no fridge or lights. The next leg of our 6 week trip may require boon docking, so having a working fridge is important b/c our cooler isn't big enough to hold all our chilled food.

So what else would you veteran RVers suggest for diagnostics or solutions? We'll be in Albuquerque 2 more nights. It's ballon festival time so it's very difficult to get in at Camping World or to find a repairman who has available time to come to us.

 

[cookie]

There are a couple of things I would check.
Take a look at the neutral buss. be sure all connections are tight.
I am not familiar with the MPG system, but there is a chance that you have a reset-able breaker. Look on your breakers and you may find a tiny reset button on the side of one of them.
It would help if you had a multi-meter and used it to track power from the battery back.

Peace
Dave

 

[danemayer]

Hi MountainTop,

As Dave suggested, it may be the manual-reset 12V automotive style circuit breaker that sits between the power converter and the battery. When it trips, the symptoms are exactly what you're experiencing. All your 12V lights, frig, furnace, thermostat work while on shore power (because they're being supplied 12V from the power converter), but as soon as you unplug, you get no power from the battery.

Here's a link to our 12V Block Diagram and Diagnostic Guide which has diagrams, photos, and a diagnostic flowchart.

Also, here's a picture of the typical manual-reset circuit breaker. It's usually mounted on a buss-bar with several others that are auto-reset. The buss-bar is usually near the battery. There might be a rubber boot covering them, especially if your battery is located outside the unit.

The reset button is really tiny and is hard for us old guys to see. Sometimes it's easier to feel for it.

Oh, if it's the reset button, you might ask for your money back from the mobile service guy.