Water Heater Probs

At campground plugged into power. At home did both gas AND electric to make sure both worked as I knew we would have hook up. I checked the breaker at my converter and all seems good. Where else is there a fuse ? I'm sure it's a lack of power issue I think as I'm not getting that switch to light inside my trailer where I turn it on to start it and then it clicks on when using gas. Not sure where else there might be a fuse. I checked all my wiring up to it and seems normal. But, I'm no electrician.

Thanks for the help if you guys can think of anything else.......