• The site migration is complete! Hopefully everything transferred properly from the multiple decades old software we were using before. If you notice any issues please let me know, thanks! Also, I'm still working on things like chatbox, etc so hopefully those will be working in the next week or two.

Question on vent switching

IROC

New member
I've searched on here for some answers and this is the first time I have came up empty handed. My problem is on my 1997 GTP with the DCC. It's not switching any of the venting positions either in AUTO or MANUAL modes. It seems to be splitting the air evenly to the defrost,vent, and floor. Not a big deal since I bought it for a work car, but it would be nice to get it fixed if it's not too expensive. I thought I would see where you guys think I ought to start looking before I tear into it this weekend. Is this still controlled by vacuum like other GM cars?
 


There is an actuator and blend door. Start looking at those two items...not sure how it is controlled on the 97's for sure
 
I thought I had an issue with mine but when I took it apart and watched the actuators, it all functioned just fine. I guess I am not used to its HVAC...

The mode door acutator is vacuum controlled and is on the drivers side of the car. You must remove the plastic close out panel and then the metal knee bloster, to see it. There are 3 vacuum actuators on the car and 2 electronic.

From what I understand, these vacuum actuators rarely go bad. The elec do fail and I replaced one of mine. When one of those fail, you do not get the same temperature on each side, even in just driver mode. Both are used for driver mode to regulate temperature.

I will watch this post and see what you find.

You should also check your vacuum line going into the car. It starts at the back of the intake, well at least on my car it does, it is a non GTP. Then the line runs across the firewall and down behind the battery, into the interior.
 
Last edited:
I got it fixed this weekend. Thanks for all the help. It ended up being the vacuum line that goes down by the battery that toolguy was talking about. It had came out of the rubber coupling, basically a rubber hose, that couples two plastic lines together right as it leaves the last clip on the firewall on it's way toward the pass. strut. Thanks again for your help.
 
Back
Top