Coach batteries not charging while engine running and MOM set to Dual

justdon57 · August 25, 2013, 12:31 PM

I noticed today that my alternator is not charging my deep cycle batteries with the motor running and MOM switch set to Dual, the battery under the hood appears to be charging well.

Madathlon · August 25, 2013, 04:27 PM

Have you check to see if the solenoid connecting the house batt to the couch batt is working? If not a simple test can tell you if it is. Removed the (+) from the house side of the solenoid from the house Batt and have someone work the MOM switch. taking a test light from the disconnected (+) cable to (-) ground it should light up when the MOM SW is set to All (Both). If the test light does not light up chances are your solenoid is bad. take your to a Auto parts store and get a new one.

Good luck and happy RVing

justdon57 · August 31, 2013, 11:39 AM

I removed the batteries from the compartment today to be able to get at the solenoid, they were completely drained. I have 2 posts on my solenoid, one to the coach batteries and one to the engine compartment battery, in order to test as you describe I need to have a full charge on one of the batteries I removed? also what is the best way to remove the nuts on the solenoid posts? i have tried an open end/box end wrench but cannot seem to get a grip on it?

justdon57 · August 31, 2013, 11:53 AM

there is also a brown and a white wire that have been cut off and taped hanging in the back of the battery box

Madathlon · August 31, 2013, 11:58 AM

No upi do not need a full charge on the house batts for this test. what you are going to test is called cross feed current. Now that you can get to the solenoid take a test light to the house batt side of the solenoid and have someone else switch from norm to duel. if your test light lights up the solenoid your good. if not you need a new solenoid.

justdon57 · August 31, 2013, 12:14 PM

when shore power is plugged in with or without house batteries should the dc lights and fans still work?

Madathlon · August 31, 2013, 02:38 PM

That depands on your RV set up, On my 84 Winni, No it won't, but my older 73 brave it would work.

justdon57 · September 03, 2013, 10:46 AM

I usually do not work on DC circuits, I bought an a/c test light, not sure if this will will work to test the solenoid?

DaveVA78Chieftain · September 03, 2013, 12:15 PM

Solenoid circuit is DC not AC. You need either a 12VDC test light or use a multimeter. Both available at an auto supply.

Dave

justdon57 · September 03, 2013, 02:37 PM

I tried the test light on the solenoid with the switch on dual and house side of the solenoid and it lights up, anything other reason my alternator is not charging the house batteries?

justdon57 · September 03, 2013, 03:04 PM

I connected my shore power again today and all the dc lights work! the problem I have is the control center on my stove exhaust fan over my stove does not come on at all, it only worked when I have coach batteries connected?

joanfenn · September 03, 2013, 05:06 PM

Hello: What we have found this year is the battery that actually starts the motor was dead??? and it affected our monitor panel. Didn't have any lights at all. We haven't gone further then that but anything dc didn't work. Does your MH start with the key? Could just be a battery problem.

justdon57 · September 03, 2013, 05:28 PM

the battery under the hood for the mh holds a charge well and fires the motor right up without a problem, I think that I read somewhere that the fan and light in the exhaust fan over the stove run on a/c, neither of those work currently, the control panel that is built in to the exhaust vent works well on coach battery only

joanfenn · September 03, 2013, 05:52 PM

I didn't think it was the same but you never know. I think that we have found that there is a problem with the wiring in ours between the three batteries because I thought the starter battery only started the mh and didn't run any of the things inside the coach. Oh well, live and learn.