My wife's 1992 960 SW no longer has AC or heat blowing from the 4 central outlets on the face of the dashboard. Plenty of hot and cold at the feet and some at the defroster but nowhere else regardless of the setting. This seems to have occured recently however she kept the heat going to just her feet throughout the winter. Am preparing to take this car on a long trip and need to have some climate control. Is this something that I can tackle myself or does it require excessive mechanical talent? Any suggestions would be greatly appreciated.