'98 Chieftain engine doesn't charge house batteries

thank you for your response. I've located the dead front you mention and there are two solenoids behind it. I know the one for the house battery shutoff works because I use that one to disconnect the house stuff when I'm away. The lights inside go out when I turn it to off.

I can't find a wiring diagram that shows which if/where the relay to charge the house batteries is, which fuse protects the solenoids and where that fuse would be located?

Thanks again!