Coach House Batteries Not Always Charging

[Smoker]

I have a 08 Forest River Berkshire.

Twice in the last 6 weeks my house batteries were not charging. The charger comes from the Magnum Energy MM-RC 1212 convertor/inverter the unit has next drawer to the house battery drawer. What seems to be happening is that the Magnum is not getting AC power to it. I used a jumper (ext cord) and by feeding AC power to it from another source it charged. This leads me to believe the MM-RC 1212 is working fine and that I might have problems with my transfer switch (IOTA ITS-50) Has anyone else had this happen?

I’d hate to spend $ on a another transfer switch if there is a easy fix here. I took it to my dealer and of course by the time I got there it was all working fine. They played with it and found nothing wrong and charged me $298. One thing to note here is that when I had the problem twice now I also have no rear air conditioner working. Forest River people think I have a bad coil in the transfer switch however over the phone and everything working fine it’s hard to trouble shoot. FR also said something about my air and that it would not work. Appreciate any feedback on this. Thanks...Ron

[wolfe10]

A non-functioning ATS (Automatic Transfer Switch) would result in no 120 VAC to everything in the coach. Do you have 120 VAC to any appliance or outlet when this occurs?

And IF (big IF) you are safe working around 240 VAC, let us know and we can talk you through how to check the ATS.

Also, does this occur only on shore power or also on generator power. That would help isolate the cause.

Brett

[Smoker]

A non-functioning ATS (Automatic Transfer Switch) would result in no 120 VAC to everything in the coach. Do you have 120 VAC to any appliance or outlet when this occurs?

And IF (big IF) you are safe working around 240 VAC, let us know and we can talk you through how to check the ATS.

Also, does this occur only on shore power or also on generator power. That would help isolate the cause.

Brett

Thanks Brett. Yes I do still have 120 volt power to everything in the coach except the rear bedroom air cond it seems. The only thing going on is the batteries not charging but when running a jumper they will charge. This occurs on both shore and gen power. Recently when checking it over it started working for about 20 minutes then quit again. Between myself and my brother yes we feel safe working aorund 240 vac. Thanks Ron.

[wolfe10]

Ron,

If safe working around 240 VAC (50 amp service):

If this is a problem with a poor or broken connection in one of the hot wires, everything running on that hot would be affected. In most 120 VAC breaker boxes, that means items supplied by every other breaker as you go down the breaker box would be affected. So, see if all appliances and outlets supplied by that hot are not working. If some are, that would verify that the ATS is not the issue, since power is getting to both hot lugs in the breaker box. Check connections (with power off) at the breaker box as well. Pay particular attention to burned or loose wires.

If one of the hot legs is not working and you have verified that the CG 50 amp outlet is correct (see below) with generator off and shore power disconnected, remove cover of the ATS. Check for loose or more likely burned wires to all terminals.

Plug in and check for proper voltage on the shore power IN and OUT sides of the ATS.

Disconnect from shore power and start generator. Re-check for voltage IN from generator and OUT to coach breaker panel.

50 amp RV outlet:

Outer straights are hots.

Center straight is neutral.

Center round is ground.

So from either outer straight to center round or center straight= 120 VAC

Center round to center straight= 0 VAC

Outer straight to outer straight= 240 VAC

Brett

[mclavey]

My coach has a power management computer which monitors the power draw and the input power and has four relays inside of the main power panel. It shuts down select circuits in sequence. I have had similar problems and it turned out to be a bad relay in the main panel. The shut down sequence is set up by the Mfg. Mine turns off the Washer first, water heater second ... front AC third .........

Yours may have the rear AC and the charger on the same circuit.

Good luck finding the problem.

[Smoker]

Well everyone, I finally solved why my coach batteries were not charging sometimes. It was a loose marret on a wire in a junction box at front of coach. Taking all your suggestions and possible causes we kept trouble shooting. The problem as we documented it seemed to be that 90% of the time it would only happen when the gen was switched on. Several tests on the auto transfer switch said it was doing its job from using shore power although we still did not have the rear air working. We then started tracing back from the generator. The gen was producing the proper power coming out of it. Tracing the wires from it to a junction box on the firewall near the gen we opened it and as soon as we moved the wires in there bingo the problem found. Seems part of these wires going to the transfer switch were also wired to run the rear air conditioner etc. This wiring set-up thru everything also sent power to the inverter/convertor to charge the coach batteries.

So as we traveled in the coach the loose wire would bounce on and off with its poor connection and sometimes work and sometimes not. Anyhow we are as back in business and I can't say enough thanks to those whom added their input on this forum.

By having others add opinions to a problem it challenges one to think and rethink.

Again thanks.

Ron

[CACONTROLS]

I turned the coach battery off and now can not get it to come back on.

[wolfe10]

I turned the coach battery off and now can not get it to come back on.

Welcome to the FMCA Forum.

Have you checked battery voltage at the battery? Digital voltmeters from Radio Shack, Sears, etc start under $15.

If battery voltage is OK, you need to troubleshoot your disconnect switch/disconnect relay.

Locate the relay.

Check for 12 VDC from one large lug (battery side)to any chassis ground with switch in either on or off position.

If no power to either large lug, check batteries and wiring from battery to relay.

Turn switch on. Check for power to the other large lug only when switch is on.

If no power to the second/other lug with switch on, take a small jumper wire from the battery side large lug to the POSITIVE small terminal (some relays have two small terminals, one positive the other ground, some have only one small terminal which is the positive and relay's ground is through the body's contact with the chassis).

If you now have power to the second large lug, you need to fix the wiring or switch. If no power to the second large lug, the relay is bad.

Brett

Brett

[Koliver]

I turned the coach battery off and now can not get it to come back on.

I had the same problem. Eventually traced it to a fuse under the bed. A 250 amp ANL fuse that looked good on the top side, but my voltmeter showed it losing 1/2 of the voltage when in use. That was enough to prevent the solenoid that turns the coach power on and off from working.

You don't say what kind of Coach you have so I can only guess that you have the same setup. Mine has a "coach power" switch by the door, and it was working intermittently, occasionally turning things on or off, but not reliably. I initially bypassed the circuit by putting another switch under the bed, on a wire so it hung out to where I could reach it without lifting the bed platform. Then a friend (electrical engineer) had a look at it and sort of found the problem. Wasn't till I got a new fuse so I could swap out the bad one, that I was sure of the problem and the solution.

Good luck! Electrical gremlins are the worst.

[rickjudy]

We need four 6volt house batteries [ read 4.7v]. 4 yrs old. Present brand Workaholic.

Comments on brand replacement?

Cost?

FMCA discount?