My 1998 oldsmobile Van has had the air conditioner repaired and charged. I was told it had a faulty ac switch? The air conditioner doesn't work. The blower works (except for the last switch position) , but it doesn't look like the ac clutch is turning. What can be the problem and where is the ac switch located? Thank you. Jim Murphy

Optional Information:
1998 Oldsmobile Silhoette 3.1

Already Tried:
Took it to a garage for repair, to no avail!