Heater Control Valve or recirculating air valve issue?
 

Hi,

I posted a thread of location of "recirculating air valves" and I locate them successfully.

Now 2 questions coming up:

1) The Heater Control Valve (see photo) doesn't operate (not moving) -- in what condition does it operate? I have checked the vacuum line that I feel sucking with my finger.

2) How to test the recirculating air valves (heater)? A "click" sound hear from recirculating air valves (air circulating) when pressing ventilation switch, but no sound on heater value when I am turning on temp switch / turn on-off AC / defrost switch.

My car is 944S2 1989

Thanks very much~~~~

http://forums.pelicanparts.com/uploa...1629195136.jpg

Did the heater valve move when you sucked on it? you didn't specify.

moving this thread to the NA forum as this car is an NA car and not a turbo car.

Check to see if the vacuum running to that valve changes when you press the ventilation switch/turn on the heat in the cabin.

If it does not, then to me, it sounds like an issue with the switch (heater control switch near the firewall where the vacuum is controlled for the valve).

If it does, likely the valve. Remove the valve and check the diaphram by sucking/blowing on the vacuum port.

According to Clarks, one other possibility is the Temperature Control Unit - I am not familiar with the operation but I think it may control the heater control switch.

What are your symptoms?

I did a video on testing the motors and solenoids linked below, as it can be hard to tell if it's the head unit or one of the components bolted to the main hvac flapper/heater core monstrosity. That said, if you you can't open and close the valve under the hood with a mityvac, you need to start by replacing that.... Also, if the heat's always on, there's a little plastic clip under the dash that often breaks.

https://www.youtube.com/watch?v=GjD0FqCNxIo&t=1s

Thanks for reply. Finally I have figured out due to vacuum leak AND broken valves. I have fixed & replaced with new valves.

However, another problem coming up. The temperature remains same (cool) while turning the climate knob. It blows full heat when turning to full right. I check out the motor on passenger side (I am right driving side) that hear no noise from motor. How to inspect the motor?

Thanks for all help!!!

Kay