2001 ASTRO VAN AIR CONDITIONING

you need a mode actuator !!

If it is blowing hot air out of the defroster and not out of the heater vents then the door that directs the heat from the defroster isn't working properly it is blocking the heat from going to the heater vents. Also check the cold air door. It sounds like it isn't closing all the way to shut off the cold air and not letting the hot air pass.

Yes it could but also check under the hood because it is a very common problem for a vaccumm line to come unhooked causing this problem. Hope this helps, Allen, swiftautorepairs.com

THERE IS A VACUUM LINE THAT GOES FROM THE LEFT FRONT OF THE ENGINE TO THE VACUUM CHECK VALVE NEAR THE ACCUMULATOR. IF THAT LINE IS BROKEN THE PROBLEM YOU HAVE IS NO HVAC MODE SWITCHING.

There is a thin vacuum hose running across the top of the engine from the front left side to the rear. this connects to the back of your a/c position switch. Over time it becomes brittle and cracks therefore leaving your vents stuck in it's last positon. Cut out the bad section and purchase about 3 feet of rubber hose at the auto store. Take a piece of the bad section with you to see which size hose will fit onto it. Slip it over the cut ends and pass it thru the space where the windshild washer fluid hose is attached to the back wall. This will keep it up and away from the heat. I had this problem on a 1997, 1999 and 2002 Astro and fixed the problem for less that $3.
John

There is a flap in your heater box that is controled by your vent switch by your heater controls. listen for a vacuum leak. that is common and hopfully the problem. there is vacuum lines that control the vent door that redirects the air to your vents.

Has your dash been messed with recently? if so i would check there first. you should hear a hissing if thats the problem.

Otherwise these also are common for that door flap to break and not switch NE more. thats the only 2 things that i can think of off th wtop of my head to be the problem. this would require the whole dash to come apart if its this problem

Michael
ASE certified

1988 astro 4.3l with ac, no air pump takes a belt number k060947 which is a 6 rib belt 95 1/4". please rate

The mode control switch is either defective or the switch has no vacuum, the motors that send the air to different outlets are powered by vacuum.

vacuum leak or your control valve is defective

The problem is a 1/8 diameter hose that runs from the front of the engine over the top and connects at the rear of engine on the drivers side. It is a vacuum hose #GM15967970 It cost about $6.22 at your GM dealer. Hope this helps Bill. My E-Mail is [email protected]