Lance truck camper not charging

[Jackrabbit41]

I have a 1997 Lance truck bed camper. Model Squire 8000 10’ 9”. It randomly stopped charging. Won’t charge off of the truck batteries or hookup. I read my manual and hit all the breakers and reset buttons. Non of them are tripped. I checked all wiring and it’s fine, and grounds are all clean. Can’t figure it out, and really annoying. Thanks y’all!