Component Function Tests

CONTROL PANEL

1. Switch ignition "ON" and set to "75" and "AUTO." LEDs should glow. If LEDs do not glow, power is not reaching control panel. Check for blown A/C fuse or broken feed wire. Using a test light, check power feed wire (pin B in 22 pin connector) for shorts, opens or disconnections.
2. With settings remaining as in Step 1, switch ignition "ON" and "OFF" several times. LEDs for "75" and "AUTO" should light each time. If readouts change each time switch is "ON," inconsistent power feed is indicated. Check for blown fuse or faulty wiring. Check six pin connector at back center of control panel for looseness or dirty contacts. Repeat test with different setting. If readout functions correctly at different setting, or fails to function correctly at any setting, control panel is defective and must be replaced.

ACTUATORS

Actuator tests must be performed with engine running at normal operating temperature.
1. Set for "65" and "AUTO." Blower speed should gradually increase to maximum. If speed does not increase, refer to "Diagnosis, Blower Control." The recirculation door will open. The air should be cold and coming out of the A/C outlets. On Regal models, compressor will cycle if ambient temperature is above 50 degrees.
2. Set for "85" and "AUTO." Blower speed should decrease, then gradually increase to maximum. If speed does not increase, refer to "Diagnosis, Blower Control." Most air will come from heater outlets. Some air will come from defrost outlets and the air will be hot. If temperature actuator does not go to maximum heat position, the "guide" LED will flash.
3. Set for "85" and "DEFROST." If blower speed does not remain at maximum, refer to "Diagnosis, Blower Control." If air does not become hot, temperature LEDs should flash indicating problem with temperature door. Defrost doors will open from bleed position. If ambient temperature is above 50 degrees, compressor will cycle. If compressor does not cycle, refer to "Diagnosis, Clutch Control." A small amount of air will come out of heater outlet.
4. Set for "75" and "BI-LEVEL." All air should come out of A/C and heater outlets. Blower speed will decrease unless there is a sensor problem. If temperature door does not reach new position, the "guide" LED will flash.

TEMPERATURE DOOR/VALVE ACTUATOR

Perform test with engine running at normal operating temperature.
1. Set for "65." Wait 60 seconds, then set for "85."
2. Observe LEDs. If LEDs do not flash as door moves, system is functioning correctly. If LEDs flash at either "65" or "85," actuator arm is out of adjustment (refer to "Actuator Diagnosis").