I would suggest this:
Goto the nearest church, find the most experienced priest and ask them to exorcise the car, you must have a holden spirit in there ....... LOL
Failing that to work, check the interior forum I think there is a recent thread on how to test the climate control to get the error code/s , try that post the codes up and lets see what we can do.
EDIT: Here is the link Error codes on climate control for ef fairmont ghia
save you some effort