So, my A/C only worked on high and switched to defrost when I accelerated. I swapped out the blower motor resistor and A/C check valve on firewall and now all fan speeds work, but air will only blow through defrost vents no matter where the dial is. Any ideas?

Thanks,
JC
1990 GT hatch

 

Either a bad vacuum canister or a vacuum leak in the hvac system

 

+1 i had the vacuum line from the vacuum tree disconnected and would do that

 

Thanks a bunch, I'll look into that

 

PS: I it located in the fender?

 

above the master cylinder is the vacuum tree

 

Cool thanks, by the way, I just got the car and have a Chilton's on the way so I shouldn't be buggin' with too many stupid questions for long.

Thanks for all the help in the meantime.

JC