Im just trying to get the heater to function. The car empty on freon from an old original compressor will not affect the blend doors from working correctly correct? I have codes for both actuators out of range. Im thinking the gear is cracked or broken.

I was testing the blower motor as it only works on high speed it has constant 14 volts at both the power supply to motor and red wire at control module. The tan wire is suppose to adjust blower motor speed correct 4-12 volts and receive the signal from the head unit to adjust blower speed at the control module.
The tan wire fed to the control module with it unplugged stays at .3 volts vs 4-12 volts or does it need the constant 12 volts, ground plugged in to have power to that tan wire? Looks like a dead end circuit. Even with the control module plugged in the blower motor power connector stays at .3 volts off and only 14.5 volts maxed out causing the blower to run full speed.

Could this be a problem with the head unit? or blower motor control module as the tan wire should have suppled 4-12 volts according to diagram and in diagram has no freon pressure circuit sensor in the actuator circuits.

Can removing the glove box and just instrument panel allow you to access and remove or manually adjust the actuators as well as access the power plugs to actuators to test for signal circuit power 5 or 12 volts whichever when actuators switched hot to cold.

 

What year is the car ??...can you edit your profile with as much info as possible...there are wiring differences on different model years....manual or auto AC

 

Its a 99 and i have all 3 99 service manuals for 99 corvette. The head unit should be putting out variable signal voltage 4-12 volts to change blower speed? Same with the actuators.

Is a 2002 ac head unit auto climate control the same as a 99. I have one i can try if thats the problem.

 

The later models use a 5 volt PMW signal so with the tan wire backprobed at either the HVAC module or the processor you should see the voltage change and the fan speed is changed...4-12 volts...you should see a lower voltage at high speed and higher voltage at low speed.

 

So youre saying the tan wire at the 3 wire plug to blower motor control module should vary 0-4-12 volts depending on fan speed or bar adjustment reading on the dash and not .03 volts until i blast it full speed reaching the 14.5-12 volts with the car running. From there the 2 wires to blower motor should vary 4-12 volts.

I was thinking the blower motor control module but if the tan wire isnt adjusting or reading different voltages when adjusted something is wrong?

 

With the control module unplugged I would expect to see 12 volts and when reconnected and backprobed 4-12 volts depending on blower speed adjustment...don't think your 02 HVAC Module will work...like I said it's a 5 volt PWM signal and looks like the 5 volts comes from the processor.