My parents have a 1998 Pontiac Bonneville SE with automatic climate control. The system has two issues. First of all, the blend doors will send air to the floor and the defrost vents, but not to the front vents. Pushing buttons on the control panel to change the vent selection produces relay clicks under the dash. Are the blend doors on this car actuated by vacuum, and if they are, is a vacuum issue plausible since it will change between defrost and floor vents (I think not, but could be wrong)? The second and more pressing issue is that the blower motor will only run part of the time. It either works as it should or doesn't work at all, and the odds of it working on a given day seems to decline as the temperature drops. Are these two issues likely connected, and are they likely to be caused by the main control module (this device appears to control everything on this system)? I'm hoping not since that module is hideously expensive, and I know little about automatic climate control systems and am hoping somebody knows if and how it can be fixed without replacing the entire control module. Getting the blower motor to work when it is needed every time is the main priority, of course. Once again, I know little about these systems, my suspicions are mostly speculation, and I am hoping someone has seen this before and can help me avoid having to guess on a $500 part.