Take a look at this thread
http://www.trailmanorowners.com/foru...ead.php?t=7789
The problem is almost certainly NOT the airco. Either wires have frayed somewhere and are making contact where they shouldn't, or something is miswired. Quite probably there is a problem with either the outlet that you plugged the TM into, or the extension cord you are using. Your first step should be to run down to the hardware store and get one of those little three-light testers pictured in the second post of the thread above. Bring it home, plug it into the home's outlet where the TM is powered, and see if the lights are correct. If so, plug it into the end of the extension cord that you are running out to the TM. Finally, if the lights are correct at that point, plug it into any electrical outlet in the TM.
By the way, you are using a three-wire extension cord, right?
Let us know what you find, and we'll go from there. Or get an electrician out to the house, pronto, as Dave suggested. But don't even think about ignoring the problem - as you know, it is dangerous!
Bill