Forum Discussion

Red_Racer's avatar
Red_Racer
Explorer
Jul 30, 2014

2008 Southwind 36D battery issue

Hi all,

I realize that battery issues have been covered in just about every way, but this issue is an odd one. Or is it? I think I know what is wrong, but need a second opinion. Read on....

This MH has 2-6 volt golf cart batts in series, that are about a year old. If I measure the voltage across both of them right now, they sit at 12.7 volts but if I use the rocker switch on the batt meter to test the Aux (coach) battery, it measures about 11.5 volts.

If I turn on a set of ceiling lights and start the engine, after about 10 seconds I hear a click, and they get brighter. This tells me that the isolator solenoid is working, and passing alternator voltage to the batteries. At this point if I use the test switch to measure, it reads 14.4V or so, and that is consistent with alternator charge voltage. However if I now measure across the battery terminals I get only 13.2.

If I measure on the Coach Battery cable coming out of the BCC, I get 14.4.

That all said, if I now shut the engine down and put a load on the batts (all lights, frige, one vent fan, Etc.) the battery test switch will now read 12.4, and falls fast. You can watch it fall to 10.5 in less than a minute (same load) and the fridge shows a "Lo Dc" error. But, if I now measure across the battery terminals, the voltage holds at 12.54.

The only thing I see that could be an issue, is the ground connection from the coach batteries to the frame. It looks horrible, and I am convinced this is the problem. I said earlier that I have 14.4V from the opposite end of the positive battery cable where it connects to the BCC. This only leaves the negative cable as suspect. I have not tried to fix that yet because I need to get the coach to my house to do it where all the cool tools are. Too much trouble to haul it all to the storage lot.

Do you all agree? OR, am I missing something here?

thx!

RR
Class A
  • Gjac's avatar
    Gjac
    Explorer III
    Aug 02, 2014
    Having an 18 year old MH I have found that most of my electrical issues were bad connections and they all tend to happen when traveling. Grounds and corroded terminals seem to be number one and two. Harder to find are corroded wires inside the terminals which have shut down my genset and inverter. A recent one was an engine no start caused by a loose arcing battery disconnect.
  • Red_Racer's avatar
    Red_Racer
    Explorer
    Aug 02, 2014
    Ionfu, right you are, and I learned a good lesson here. Batteries have existed for ever, haven't really changed, and most likely never will. You can have transfer switches, battery control centers, solenoids that move power around, etc., but it is still a battery that can have dirty connections!
  • lonfu's avatar
    lonfu
    Explorer
    Aug 02, 2014
    I pulled into the Valencia Camping World many years ago to find an old couple in their moho with out power. He was an electrical engineer and she was a college professor. Such nice folks. CW was real busy and couldn't get to them for a few days. They were with out power. I asked if they wanted some help, and both were desperate for the water pump so that they could flush the toilet. Peu!!!

    Worked as a AAA driver for a couple of years. Took my hammer and taped on the frame to battery ground wire connection. Problem solved in 1 minute. Batt terms looked like he had just cleaned them, he had. Water pump still wouldn't function, tested juice to pump, it was ok! Took hammer taped on water pump, It grumbled and then it fired right up! He had a spare pump that he had rebuilt and saved, they stayed over night next to us and were on their way the next morning!!!! Got to remember folks, it is only 12.8 volts, got to have bare metal to bare metal for good current and voltage. When in doubt, clean BOTH ends of your battery cables....... and then use petroleum jelly on the terminals.

    Old mechanic told me once, "petroleum jelly, good for butts, balls and batteries". Most low speed ball bearings can be lubed with PJ and they charge big bucks for petroleum spray for your battery terminals. As for the last, well, sure makes a fella grumpy when you have a sore a..! So, you should keep your batteries and balls as you would keep your butt, CLEAN! And all will be happy!!!!!!
  • Red_Racer's avatar
    Red_Racer
    Explorer
    Aug 02, 2014
    Problem solved....Batteries are now receiving converter, and alternator voltage the way they should.

    The whole ground array was a mess,corroded,yuk.

    However, it is hard to believe that Fleetwood did the grounding the way they did. There are two bolts in the frame where the coach battery grounds attach. One has 7 small wires on a 1/4" bolt running through the frame which is nutted at the base, then 3 more nuts that hold the small wires separated by star washers. that isn't bad, but the main battery ground has the same bolt arrangement except that it goes through a 3/4" hole (1/4" bolt)and has flat washers on each side of the frame that are intended to be like a reducing washer, so the corrosion was building up around the rim of the washers.

    Solution was to drill a new 5/16" hole, grind/brush the undercoating off of the frame, then hook the main ground with a star washer on each side to the frame.

    Far better connection now, and a coat of paint finished it all off. If you all run into this, my solution isn't that hard to do, and seems a better way.

    thanks for the comments all!

    RR
  • Red_Racer's avatar
    Red_Racer
    Explorer
    Jul 30, 2014
    Guys,

    Thanks for the comments so far. Matt's note on replacing the meter in the panel is an interesting one. I actually think it is working just fine, though it is not measuring the voltage at the batteries but instead from somewhere inside the BCC. Probably off of one of the solenoids or maybe from a spot on the circuit board.

    That is what tripped me up in the first place. If the meter in the panel says all is good, and it is not all good (my case) what do you believe? I'll fix the grounding issue this weekend and post back if that fixed it. If it doesn't fix it, then I hope you all have suggestions!!

    RR
  • Matt_Colie's avatar
    Matt_Colie
    Explorer II
    Jul 30, 2014
    I do (did before the depression) boat electrics.

    From what I read, you did a good set of tests that says that you have a bad connection to your house bank. If cleaning and reseating all of them does not cure your problem, look for the one you can't find. When you get done, if the panel meter does not agree with the hand held (assuming that the later is decent quality), get an new panel meter. Those are often less than stellar parts.

    Matt
  • othertonka's avatar
    othertonka
    Explorer
    Jul 30, 2014
    You can do this test to prove the bad ground. Put the positive test lead from your meter on the positive terminal of your battery and the negative test lead on the frame on a bare metal spot near the ground connection of your house battery and see what reading you get. reading for a fully charged battery should be 12.7. Compare that reading with the reading you get from testing Positive to negative right at the batteries. If your ground is bad the readings will be different between tests.
  • darsben's avatar
    darsben
    Explorer II
    Jul 30, 2014
    I agree that is the best place to start. Clean all connections and make sure they are solid is usually the first step in troubleshooting battery power problems

About Motorhome Group

38,707 PostsLatest Activity: Feb 17, 2025