B: Elec. Door Actuator Motor Inop, Intermittent, or Improper

PINPOINT TEST B: A/C ELECTRONIC DOOR ACTUATOR MOTOR INOPERATIVE, INTERMITTENT OR IMPROPER OPERATION

B1 CHECK SYSTEM FOR TEMPERATURE CONTROL

- Start vehicle and run engine until it reaches normal operating temperature.
- Turn on MAX A/C mode.
- Turn temperature control knob to full COOL (left) and check for cool discharge air.
- Turn temperature control knob to full WARM (right) and check for warm discharge air.
- Vary temperature control knob from full WARM to full COOL.

- Did air temperature change?

- Yes
System is fully functional.

- No
Go to B2.

B2 CHECK FUSE

- Check Fuse F5 at the fuse junction panel.

- Is fuse good?

- Yes
Go to B3.

- No
Replace fuse. Go to B1. If fuse blows again, CHECK for shorts to ground in Circuit 298 (P/O) and SERVICE as needed.

B3 MANUAL A/C ELECTRONIC DOOR ACTUATOR MOTOR SUPPLY VOLTAGE CHECK

- Disconnect A/C electronic door actuator motor connector located on the heater air plenum chamber accessed through the glove compartment opening.
- Using a test lamp, check for battery voltage between Circuit 298 (P/O) and Circuit 208 (GY).

- Did test lamp illuminate?

- Yes
Go to B4.

- No
Check Circuits 208 (GY) and 298 (P/O). Restore vehicle. Retest system.

B4 CONTROL HEAD POTENTIOMETER SUPPLY VOLTAGE CHECK

CAUTION: Never jumper Circuit 436 (R/LG) to Circuit 600 (DB). This could destroy A/C electronic door actuator electronics.

NOTE: The A/C electronic door actuator motor used on manual (non-EATC) systems can be tested to determine if the actuator and circuit from the A/C control is operating properly using the following procedure.

- In-Vehicle Actuator and Circuit Test. Remove the A/C control and disconnect the harness connector from the temperature control potentiometer. With ignition switch turned to RUN and the system in any position except OFF, jump from the potentiometer harness connector center pin to one of the side pins. The actuator (and temperature blend door) should operate in one direction. Then, jump from the center pin to the other side pin. The actuator should drive in the opposite direction. If the actuator and temperature blend door do not operate in both directions, either the circuit from the control potentiometer to the actuator or the actuator is at fault. Test the circuit and actuator separately to isolate the condition.

- Actuator Only Test. Apply positive (+) battery power to Pin 7 of the actuator and connect the negative (-) lead to Pin 8. Jumper from Pin 3 to Pin 4 of the actuator. The actuator shaft should rotate in one direction to the stop. Then, jumper from Pin 3 to Pin 6. The actuator shaft should rotate in the opposite direction. DO NOT jumper Pin 4 and 6 together. this will create a short. Reconnect A/C electronic door actuator motor connector at the heater air plenum chamber. Disconnect heater control connector from the back of the A/C control.

CAUTION: Never short across Circuits 436 (R/LG) and 600 (DB) as this could cause destructive damage.

- Using a voltmeter, check for reference voltage (approximately one to two volts less than battery voltage) between Circuits 436 (R/LG) and 600 (DB).

- Is the voltmeter registering one to two volts less than battery voltage?

- Yes
Go to B5.

- No
Check Circuits 436 (R/LG) and 600 (DB) for opens/shorts. Restore vehicle. Retest system.

B5 CONTROL HEAD POTENTIOMETER CHECK

- Disconnect and remove control head potentiometer.

- Check resistance between terminals 3 and 2. With potentiometer at full COOL, resistance should be 3000 ohms. With potentiometer at full WARM, resistance should be at 15 ohms.

- Is resistance linearly variable from COOL to WARM?

- Yes
Replace A/C electronic door actuator motor. Restore vehicle. Retest system.

- No
Replace potentiometer. Restore vehicle. Retest system.