Air vent problem
I noticed today that my 1988 Southwind has no air coming from the dash vents when the blower is on. I removed one of the flexible air ducts from the chute that the blower is hooked to, there is what ...
Forum Discussion
HVAC systems at that time used vacuum to operate the flappers. If you lose vacuum they default to defrost mode (for safety purposes) which is what you are describing. Some place you have lost vacuum. There are several flappers in the system and the mode switch on the dash is a vacuum switch so there are many possible places to leak. It is probably due to age, but could be due to mouse damage. You will have to find and fix the vacuum leak.
