93 940 wagon nonturbo:AC control

Lou Rosenbaum · Post by **Lou Rosenbaum** » 17 Aug 2008, 18:10

While highway driving, passing or hard acceleration, the air will move from the dashboard vent to the floor vent. Let up on the gas and air moves back to dash vents. Very repeatable. I first thought it only happened when going up a hill. Wasn't till I was passing on level ground that I realized it was not happening cause of the hills but because of hard acceleration.
Thank you for you attention
OUT OF MY LEAGUE LOU
"250,000"

Post by **billofdurham** » 19 Aug 2008, 15:30

Is this the manual or electronic climate control system?

Bill.

Lou Rosenbaum · Post by **Lou Rosenbaum** » 25 Aug 2008, 14:01

Manual climate control

Post by **billofdurham** » 25 Aug 2008, 15:54

The direction of airflow on the manual climate control is controlled by airflow mode doors which in turn are controlled by a vacuum actuator on the left side of the heater distribution housing. Their position is set by the centre knob on the control panel. As the airflow changes when you increase power to the engine I would suspect that one or more of the door actuators has a vacuum leak allowing it/them to move without you changing the controls. As the power comes off the engine it/they resume the proper position.

Bill.