1995 Buick LeSabre AC Problem

I’ve got a 1995 Buick LeSabre that has a curious problem with the air conditioner. The AC blows good and cold, but when I accelerate the air stops blowing from the vents. I can still hear the fan running, so it’s like the air is being redirected somewhere. Now, once I get up to speed after accelerating, if I let off the accelerator for a second, the AC resumes blowing normally. Can anyone help me out with this problem? Thanks!


You most likely have a bad vacuum check valve.

What you’re expierencing with the AC might be normal. The AC is controlled thru the ECM. So when you accelerate suddenly the ECM shuts the compressor down so it doesn’t draw power from the engine so you accelerate faster. Like trying to pass a semi on a two lane road. Once you get off the accelerator and get to cruising speed again the ECM turns the compressor back on and you get cold air.


I thought he said it stopped blowing air altogether, Tester. Forgive me if I read it wrong.

Since OP can still hear the blower, I suspect the air has been defaulted to the defroster registers.
That is exactly what happens when you have a vacuum problem.

Yes, it stops blowing thru the vents but the blower fan continues to run. I suspected a vacuum problem but wasn’t sure. I will definitely be looking at the vacuum check valve. Is this something that I would be able to check and repair?