Pontiac Repair: Air Conditioning/Heating, fan speed control, pontiac transport

Question
QUESTION: I have a 1998 Pontiac Transport.  When using heat or A/C the air blows out of all vents simaltaniously.  Turning the air directional switch makes no difference.  I can hear a click when I switch to defroster but no difference in air flow.  The fan speed control and temperature controls work.  When ignition is on there is a wirling sound coming from the blower motor area as if the vacuum is trying to switch the air flow.  How do I regain directional control of airflow?

ANSWER: Hi Dennis:

That van uses an electricaly controlled hvac motors not vacuum controlled like the older cars and vans. My guess is the linkage jammed up on the hvac module. The mode switching linkage and the actautor motor is on the left side of the HVAC box. either the linkage jammed up or came off or the electrical actautor is to blame for the issue here. Without seeing it I can't tell you for sure. I can't explain the noise you say you hear as a vacuum noise. Good luck :)


---------- FOLLOW-UP ----------

QUESTION: Thank you for your prompt reply!  I have removed the Heater and air conditioning control assembly and have disconnected what is called a vacuum harness and reconnected it without any positive results.  I can not track back all the tubes coming from the harness but have tracked at least one to front blower motor.  Is the actuator motor inside the blower motor or around it?  I can not visually locate it.  Thank you!

Answer
there is a actuator by the blower motor but that doesn't have any effect on the air flow into the van's cabin. that actautor by the motor is the air inlet door it chnages the inlet air to the motor it chnages the inlet air inlet from either outside air or it recycles the air that's inside the van.