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brutherb · 12-27-2023, 07:33 PM

new to me coach that has been sitting for a while. so i am sorting out some issues. today i replaced the converter as i was getting no 12v in the coach. that fixed a bunch of stuff. when i put my multi meter on my start battery i can see it is being charged by the converter (13.06v) but the coach battery is sitting at 12.54 so not being charged. i am assuming it is one of the 3 solenoids. its dark now so i cant go confirm but the first solenoid (automatic charging and aux start) measures 13.06 at the top and 12.54 on the bottom. should this solenoid open to allow both batteries to charge off the converter or alternator i didn't clue in that the bottom was likely the coach battery. my diagram i have doesn't show where the coach battery attaches to the system. so any help on how the system supposed to behave that would be helpful. if i cycle the solenoid open and close a few time might this fix that issue.

twinboat · 12-27-2023, 08:48 PM

Check the top and bottom voltage of the auto charging solenoid with the engine running. It should show 13.5 on both large terminals.

Do the same check with the aux start switch pushed and held. Volts should be the same.

If it checks 13.5 or the same, it's working.

You may not have bi-directional charging, meaning house to chassis battery charging.

Gary RVRoamer · 12-28-2023, 10:04 AM

A Southwind definitely does have bi-directional charging (a battery charge controller or BCC). Probably an RV Custom Products module in that coach model. Whether the new converter is properly connected to it is anybody's guess.

In the usual Fleetwood RV design, the house (Aux) battery is directly charged by the converter and the BCC relay manages whether the chassis (engine start) battery is also charged. Since you say the start battery is getting charge voltage, that part must be working. However, 13.07v is a bit low - I would have expected the 13.3v-14.3v range.

If the house Aux battery is not receiving a charge, I can only guess it is not wired in properly. Start with verifying its battery plus cable (from the converter) and the negative ground cable.

brutherb · 12-28-2023, 11:31 PM

It is an rv custom product bcc. It was original wiring I believe didn’t look tampered with. The power goes from the converter to the coach power center and it’s getting back to the bcc in the front of the coach. Which I believe the coach battery ties in at (the bcc). I have the diagnostic guide will be going through the steps tomorrow, for me it’s a bit more complicated than I’m used to and I did t get it working 100% so I am working through the issues one at a time. So any help. Would be appreciated. I

I am guessing as well the converter should be changing the house abd the start batteries

If the aux start solenoid has the start battery on top abd the house battery in the bottom when the aux start buttons pushed would the voltage not be a blend of the 2 batteries, that’s why I am wondering if it is opening or not, right now they are reading 2 different voltages