It has a (breaker) reset on it. Did you try that?
Also, the shore power plug on the van is probably a square one that says Marinco. Someone had one fail badly recently. Unscrew it from the van body and pull it and check your connections there. The breaker reset idea above probably won't help since it is obviously inverting, just not charging. Sorry, just reread post but wanted to leave that there in case you hadn't noticed it has a reset.