I think it could be for the solar power. It doesn't work on any lights ,USB or the tv. Your USB that's not working. It's garbage, your door lock cost $20.Install a digital fob lock. No more small purple key. Awesome. Worth the $120 I installed USB rockers. They work a lot better for like $10 to $20. 2 switch boards in bathroom and 3 in front living . That's a joke. $20 and under we could put them on one that glow at night and have usb. I payed $38k for my 36ft.Heartland makes great rvs just cheap garbage on the inside