Auto Parts: Dual climate control, vacuum tester, vacuum motors

Question
Hi Mike I have a 1996 Monte Carlo with driver/passenger controls. I am having a problem with the A/C. The weird thing is its working and taking moisture out of the air but not getting cold. The system is fully charger, the clutch kicks on and the sensors for the system pressure all seem to be working well. I have a feeling it may be something inside the passenger compartment that may be the issue (driver/passenger controls?). Any advice?

Answer
    You've got air coming out of the dash, but it's not cold?  There is probably a problem with the mixing doors.  They open and close to regulate the mixture of hot and cold air that reaches the cabin.  The motors that move them can fail.  In the case of the Monte Carlo, I believe that they are vacuum motors.  A vacuum leak can cause them to stop working.  In older cars it was easy to reach up into the space under the dash and feel the levers to see if they moved.  In the Monte Carlo it's much more difficult, although the system really isn't much more complicated.  If you feel up to it, you could pull the dash and console apart to examine the system.  First thing to do, though, is to find the lines under the hood bringing vacuum to the HVAC system and put a vacuum tester on them.  If they won't hold a vacuum, then there is a leak.  If they do hold the vacuum, then some foreign matter may have worked its way into the box and blocked the operation of the doors.  This will require taking the whole box apart.  Debris from the outside can enter the system through the cowl vents, and accumulate over time.