HVAC question

[ctflash1]

Hey guys quick question about my 85 GN. Im sure all of the ventilation is the same on all of these cars but does anyone know off hand why I cant switch from defrost to vent to floor, etc.. Is the damper vacuum or electric? I havent even began to look yet just figured I would throw this out there cuz Im sure one of you have had this problem before. Thanks for any info, Steve

 

[klmnla]

I slid my control unit out the dash and saw that the round assembly with all the vacuum lines had cracked. I repaired it with some JB weld, but I believe they make a replacement part. Either way, verify all the vacuum lines are secure and not leaking on top of the control unit.

 

[ctflash1]

Thanks for the info. I'll pull that control unit out and check it out. Thanks for the help it saves me from starting from scratch troubleshooting it.

 

[rev. 3:11]

Also check all the vacuum check-valves; they are the little gray/black wafer looking doo-dads ; they can go bad and cause these symptoms

D