I have no heat on the drivers side and lukewarm heat on the passenger...this lead me to believe the heater control valves may be malfunctioning so I pulled the valve out last night and it didn't look gunked up but the plungers also didn't move when adjusting the temperature knobs or unplugging the electrical connector.

So here's the weird part. I then decided to check the voltage to the valve with a voltmeter and I get 4V at all times. This has me stumped. Do you guys think it may be my heater controls module?

 

turn on your windshield defogger ...the heater control valve usually fails in that position ...you can get heat until you fix the problem

 

Thanks, but defog spits out cold air on the drivers side and a little bit warmer on the passenger side.

So my valves are working....When testing in extremely cold, they are going to stay open no matter what the temperature is set to as the knob's range is warmer than the car's interior temperature.

I got the valve to move by turning the heater off or using INPA.

Im going to start a "no heat" thread to try and get some input on the issue.