Problem with AC/Heater vents on 2000 Safari

[djb1958]

Our 2000 Safari has developed a problem with the vents. The AC and heater work, but the air will no longer shift from the defroster and floor vents. Is this a vaccum problem maybe?

[awd owner]

I just fixed that problem on my 99 awd safari remove the air intake and filter housing there is a vacume line in front of the throttle body that was broken and I had no control of the position of air in the vehicle try that and you should be on the way.

[louu]

I am an owner of a 1998 Chevy Astro with rear heat and rear air. My problem was only cold air out of the rear heat and only the front defrost vents worked and the temperture selector not switching from hot to cold. I will try to be as detailed as possible. Lift the hood, and look at the large black box on the top left side of the engine. Just behind the AC reservoir, there is a vacuum line attached to the large black box on top right side, that looks like a Tee fitting with three connections. One went to the float switch on the bottom right of the larger black box near back, the other goes straight down to the vacuum ball located on the frame of the vehicle (underneath). The last is a thin vacuum line that looks like an electrical wire. Pull on all three lines one at a time. If one pulls all the way up to you, that is the broken one. The thin vacuum was broken in half on my Astro. The fix was to remove the air filter tube (the 3" flex tube that goes to the backside of the air filter box). Once removed, look for a flexible black tubing about a 1/2 inch round that should look empty because your line is broken. Pull the tubing to reveal the other half of the hose and reconnect with tubing that will fit over the thin black wire. Not sure what size, but what I did notice is that this was probably the same problem that GM fixed before when the vehicle was under warranty because my line looked repaired but was broken in a different spot. Before I reinstalled the air box tubing, I did wrap the entire flex tubing line with aluminum foil to help block the heat. I am not a professional, but I tried this and it worked for me. Good luck. This. feels like the scene in Independence Day when they figured out how to bring down the spaceships in the sky. Good luck

[srt4400]

thank you for the info I have a 2000 gmc safari and I had the same problem you did back in 05, I did what you did and spend $5 on vaccum line and save me cuple of hundred $$$$$$$, thank you so much