MPG 181 Electrical (DC) problem

2get2me

Member
On our first trip this fall with our new MPG 181 we encountered a strange electrical issue. The campground we were at lost 110v power in the middle of the night during a storm. We got up to check things out and turned on a couple of lights, obviously now on battery power. The lights stayed on for a few minutes and then all went out. At the same time the small fan in the electrical control unit would cycle for 4 or 5 seconds. After 20 seconds or so, the lights came back on. This on and off cycle continued until we just turned everything off and went back to bed. Both batteries (I added a dual battery setup) were fully charged. When we returned home, I tested it again and got the same result. When I next tested it with the our tow vehicle plugged in AND running the problem seemed to disappear. Turn the car off, problem comes back. The dealer wasn't able offer any explanations as to what the problem is. Anybody else had similar issues or any suggestions to offer??

Thanks,
Scott & Cathy
 

danemayer

Well-known member
Hi Scott & Cathy,

If I'm following, when you're plugged into shore power everything works. When you have battery power from the car, everything works. When you're operating solely from your RV batteries, it doesn't work.

I'm not familiar with the MPG or the electrical control unit you mention, so let me speak in general RV terms.

Your 12V lights and other things are not getting power from your batteries. When on shore power, things work because there is an alternate 12V pathway from the Power Converter (which also charges the batteries). When hooked up to the car, there is an alternate 12V power source in the car. When neither of those power sources is available, you have a failure because power is not getting from your RV batteries to the fusebox.

On many RVs this can be caused by a tripped 12V circuit breaker. I don't know if the MPG has one, but if it does, it's likely near the battery. There will be a very, very tiny reset button on one end. When this breaker trips, and there's no alternate power source, you'll have a complete failure on 12V systems.

Since this isn't the exact symptom you're experiencing, you may have a different problem with the batteries. Perhaps a loose connection or a loose ground post that allows some current to flow, but not enough.

If all the connections look good, I'd try removing 1 of the 2 batteries. If the problem remains, try running off the other battery. That would eliminate a problem caused by an internal failure on one battery.

I'm surprised that your dealer tech has no ideas about what might cause the problem. That doesn't bode well for getting things fixed at this dealer.
 

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jnbhobe

Well-known member
Everything Dan said and check the converter out because the cooling fan runs so much and also the 3 fuses on the converter.
 
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