Hi, We are new to this. we have a flagstaff t21tbhw. It is currently plugged into our house with a 30 amp converter. the first couple of days we slept in it to try it out and everything worked fine. a couple of weeks later, the fan won't work and the lights are very dim. the air conditioner works great. It's as though the battery is going dead (or is dead) to the lights and fan, but since we're plugged in, that shouldn't matter, should it? Any tips on what is going on? thank you!