i just purchased a used 2008 Jayco 1206. I failed to check the lights etc when buying it♀️ The lights work when plugged in but once I unplug they go off. I checked the fuse and it looks fine. Just dead battery? Without a volt meter I’m not sure how to test them. If I need to replace the battery then what’s the best to replace with? I think the current ones are golf cart batteries, there’s 2 of them.