Air Conditioning question

[Philossifer]

Originally Posted by Ieatcamaros

Where does this "diverter" get it's vacuum source, particularly on an 89 gt?

Thanks for the link, Maroon5.0.

To be honest, I'm not real knowledgeable about the vacuum routing on these cars. I do know for sure that the temperature blend door is controlled by a cable, but the switch that selects where the air goes (vent, floor, defrost, etc.) is vacuum controlled.

I guess the first place to start is by determining if you have enough vacuum. (Do you have a brake bleeder like a "MightyVac”?) They're pretty cheap and well worth the investment, plus they’re great for testing for vacuum leaks.

On the firewall is a “Vacuum-Tree" that gets its source of vacuum from the intake manifold. From there, the Tree sends the vacuum to deferent places where it's needed on the car. One place is the A/C Heater control in the dashboard. Hook-up the MightyVac to the Vacuum-Tree in place of the hose that goes to the intake manifold. Pump up the vacuum and watch the needle on the gauge. It should hold the vacuum for several minutes. If the vacuum drops rapidly, you'll have to start checking all the vacuum hoses including the one leading to the heater control and the control itself. If it does hold vacuum, try operating the heater control with the engine off using the MightyVac as the source of vacuum. If the control works, then you know you don’t have enough total vacuum at the tree when the engine is running.

Maybe someone else can give you more information about checking out vacuum problem....Like I said; it's not really my expertise!
Good luck,
Phil