Battery not charging. when plugged into shore power

Have your batteries load tested - most places that sell batteries/tires/auto-parts will test for free.
.
If your lights get brighter when your hooked to shore power that's likely an indicator that your converter is working. If not then it might be fuse related. There is usually an auto reset circuit breaker near the coach battery - if that blows then your battery won't charge - best to Google to get a picture because it doesn't look like std circuit breaker. Also check the fuse on the converter.