1997 Seville STS passenger climate control
 

I just recently purchased a 1997 Cadillac Seville STS with 120,000 miles. At first the problem was the blower fan motor not working, so replaced that. Then No A/C had my mechanic check it out and the Compressor was leaking, so replaced it and the dryer and nozzle.
Now I have A/C working blowing cold out of the Driver side dash vents, but the passenger side is getting warm air. Tried adjusting the Passenger temp control hot or cold and does not seem to matter. Is there another actuated door that is pushing hot air through these vents?
If so where do I find it and what is the fix? When my wife rides in the car, I get cold air and she gets HOT air blowing on her.

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It probably has a bad actuator for your wifes side.
The air temperature is controlled by the movement of an actuator. A dual zone system (CJ2) has two actuators, the actuator on bottom of the HVAC module assembly controls the temperature for the driver and, the actuator on the top of the module assembly controls the temperature for the passenger.

After an actuator has been replaced, the actuator needs to be recalibrated for proper travel. The ignition must be cycled ON for three minutes to allow the programmer and the actuator(s) to recalibrate for proper travel.