air only blows out the defroster

[rituy]

I have a 1998 Lesabre. Manul climate control.
No matter what is on air, heater, etc the air
only blows out onto the windshield. The
vaccum controled valve seems good and
has strong vaccum. Are there any controls
other than the one the vaccum lines run to
and what is it called?
Dave

[BNaylor]

Welcome to AF.

Your post was moved from Buick Tips & Maintenance to the LeSabre Forum.

Are you sure accessory vacuum from the upper intake manifold feeding to the HVAC system is really good? How did you check it? Sounds like a bad or leaking vacuum line before it feeds into the firewall and HVAC actuators based on your symptoms.

[ghink]

I had the same problem with my 97 LaSabre and found the vacuum line to the vacuum tank rotted away where in attaches to the tank. Tank is located under the battery.

[MikeS21]

I had the same problem with my 96 LeSabre. My mechanic used simple electrical tape to patch a vacuum hose. It was a five-munte job, and he said the tape would hold for quite a while.

[gjohn3707]

can anyone describe where that hose might be? I have the same problem on my 1999 century.

[imidazol97]

Originally Posted by rituy

I have a 1998 Lesabre. Manul climate control.
No matter what is on air, heater, etc the air
only blows out onto the windshield. The
vaccum controled valve seems good and
has strong vaccum. Are there any controls
other than the one the vaccum lines run to
and what is it called?
Dave

Do you get switching of indicator lights when you push on different buttons on the control head for the HVAC?

With the motor running you should hear one or more vacuum doors move as you switch among the different settings, if you have vacuum.

To test for vacuum, try the vacuum storage tank under the right front fender in front of the wheel. Lie on your back and look up. It has one hose snapped to it.

If the motor's running and just been shut off in 10 seconds, when you pull that hose off you should get a whoosh as air goes back into the tank.
The 1/8 inch black plastic line starts on the intake manifold goes to the area of the accumulator for the AC freon. It's bundled in with electrical wires. It has a Y there. ONe end goes inside under the dash. The other direction goes to the tank in front of the right wheel.

Inside the car you need to take off the hush panel under the right dash above the passenger feet. It has about 3 screws and then a couple of thin metal taps on the firewall end. The tubes coming from the vacuum control for the Programmer with the manual unit has a purple tube that goes to the right side of the car up high on the firewall where it goes to the engine compartment; but it meets the black tube from the engine. Pull it apart at the connection to check for vacuum coming in.

A couple people have found the connection came apart there. Mine were almost frozen since they'd been together for 6 years or more.

First you might check fuses for the AC to be sure you have that if the lights on the buttons don't change? Or check even though they do change.