So. I have been having a problem with the a/c vents getting stuck in the defrost mode on and off in the minivan for a while now. But then it will magical work fine again after I take it easy on it or it sits for a awhile turned off. Everything seems to be working fine when I check it. And if I drive around easy it works great. What I am thinking tho is. The actuator that controls the mode is seeing boost and getting stuck, making it go to the default defrost mode like if it is unplugged and seeing no vacuum. Is there something inline on the vacuum line for the GTP's like a check valve to stop boost from doing that? Granted the Montana was never designed for boost. So I don't see them having this problem. I have the vacuum line hooked up on the blower just like a GTP would have. Any thoughts on this?
