C3 1970 heater control vacuum valve

[Bob H.]

When you have a non air car and the valve I took out has 4 ports, are you supposed to use the 9 port valve since I don't see a replacement for what I took out? Does the 3 port valve on the other side of the controls just operate the rear ventilation? The replacement 9 port does not hold vacuum with all ports blocked. Maybe I have a bad one.

[Mark E.]

Re: C3 1970 heater control vacuum valve

I've only worked on AC cars, but suspect you need a non-AC vacuum switch that matches the number of positions on the control dial.

I don't trust the quality of aftermarket sources for parts like this, but have had good luck with used original HVAC controls from eBay.

And definitely test components and overall operation before buttoning up the console. You don't want to tear that apart any more times than necessary. A vacuum pump makes this easier.