VX Commodore A/C Problem

[Joey24]

Hi, I have VX Commodore and noticed today being a hot day in Canberra that the a/c is playing up. At the moment the a/c only blows cold air through to the windscreen to demist the windows but does not blow cold air through the front and feet vents when I change the setting. It actually makes a hissing sound when I change the setting to the feet or front air vents and continues to blow air through the windscreen vent.

Has anybody experienced the same problem and how can this be fixed?

Thanks in advance for any help.

[tezza]

Could be one of the vacuum lines behind the centre dash console popped off.

[Mick1988]

It's usually the vacuum valve in the engine bay. Will be a small white cylinder attached to a thin hose. On a V6 motor this thin hose will be attached to the back of your plenum chamber. The white cylinder contains a one way valve which you can test by trying to blow air through it with your mouth. If air goes through both ways the valve is rooted.

[VS Natic]

Hissing sound points to there being vacuum supplied to the switch. My bet would be that one of the switch hoses have come off or split.

[Joey24]

Thanks Mick, sorry about this but I had a look for the white cylinder to check if the hose popped off but I could not find it. Any chance you or someone could post a picture of the white cylinder and the hose to assist me with locating it.

Thanks.

Jo.

[Hot-Rod]

This thing.

[Joey24]

Thanks Hot-Rod for your help. I will check it out now.