RickH

1972 Cutlass convertible with A/C. When I put the control on VENT and turn the fan on, very hot air comes out of the vents, even on cool days. the temp control is all the way to the left on cool.

The heat, A/C and defroster all work as they should and the cool to hot control on the dash works fine.

Any ideas about this hot air coming through the vents?

MDchanic

Does your hot water valve work, and is it connected?

- Eric

RickH

Eric,

First of all , thanks for the quick reply. I'm a newbie. What's the hot water valve and where should I look for it?

MDchanic

It's a vacuum valve screwed into a hole in the passenger side rear of the intake manifold.

It turns off the flow of water to the heater core when you select "High Cool" or push the temp. lever all the way to the coldest position.

- Eric

Mike77

If you need one GM has them. I just bought one and it's perfect.

Mike

MDchanic

Also on the shelf or one day away at your local auto parts store.
(Note that there are a few variations for different years and models - some close when vacuum is applied, others open.)

- Eric