Do a search for 'trouble shooting Trane model # ______'
There's probably some places that will give you some tips. May or may not be an easy fix.
Our heat pump fan motor shot craps a couple weeks ago, so I know what you're going through. From what I read about ours, the motor was going to be around $40, supposedly not bad to repair, BUT the cautions of needing to know where all the hot wires, etc were was enough for DH to say he wouldn't risk it. In the end, the bill was $176 for two trips out here and the motor was under warranty.
Anyone around there have a window a/c that you can use? That and some strategically placed fans can keep your house reasonably cool. That's all we had the first year we lived here.