I just returned from a trip to the Mothership in Jackson Center to resolve my A/C problem. Airstream installed a new logic board - but the A/C compressor would still not kick in. The end result was that we replaced the entire A/C unit - as it appeared that the problem was "loss of coolant." Jackson Center is not equipped to "break in" to the system and there are no "ports" available for testing the coolant pressure. Since this is a "heat pump" unit, the net replacement cost was over $1500, plus labor. The thermostat also had to be replaced since the new units have 5 buttons vs 4 and there is no way to modify the wiring. The only "salvageable" items were the mounting pan and the interior vent assembly. This was a hard pill to swallow for a unit barely five years old! I hope that you have better luck!
2003 GMC 3500 D/A, CC, LB, 4x4 and 2000 Airstream Excella 30. WBCCI 7074