E: NO OPERATION IN ALL TEMPERATURE SETTINGS

PINPOINT TEST E: NO OPERATION IN ALL TEMPERATURE SETTINGS

E1 MANUAL A/C ELECTRIC BLEND DOOR ACTUATOR SYSTEM CHECK (CROWN VICTORIA/GRAND MARQUIS)

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

- Did air temperature change?

- Yes
System is fully functional.

- No
Go to E2.

E2 MANUAL A/C ELECTRIC BLEND DOOR ACTUATOR SYSTEM FUSE CHECK (CROWN VICTORIA/GRAND MARQUIS)

- Check Fuse 17 at the fuse panel.
- Is fuse good?

- Yes
Go to E3.

- No
Replace fuse and Go to E1. If fuse blows again, check for shorts to ground in Circuit 247 and repair as needed.

E3 MANUAL A/C ELECTRIC BLEND DOOR ACTUATOR SUPPLY VOLTAGE CHECK (CROWN VICTORIA/GRAND MARQUIS)

- Disconnect blend door actuator connector located on the heater air plenum chamber and accessed through the glove compartment opening.
- Using a test light, check for battery voltage between Circuit 247 and Circuit 246.

- Did the test lamp light?

- Yes
Go to E4.

- No
Check Circuits 247 and 246 for opens/shorts.

E4 A/C CONTROL SUPPLY VOLTAGE CHECK (CROWN VICTORIA/GRAND MARQUIS)

- Reconnect blend door actuator connector at the A/C evaporator core housing
- Disconnect heater control connector from the back of the A/C control.

CAUTION: Never short across Circuits 470 and 243. This could cause destructive damage.

- Using a test light, check for reference voltage.

- Did test lamp illuminate?

- Yes
Go to E5.

- No
Check wiring for opens/shorts. If wiring to potentiometer is good, replace the A/C control.

E5 A/C CONTROL POTENTIOMETER CHECK (CROWN VICTORIA/GRAND MARQUIS)

- Disconnect and remove control head potentiometer.
- Using a multi meter, check resistance between terminals 7 and 14.
- With potentiometer at full COOL (resistance should be 3000 OHMS).
- With potentiometer at full WARM (resistance should be 15 OHMS).

- Is resistance linearly variable in between cool and warm?

- Yes
Replace A/C electronic door actuator motor on heater air plenum chamber.

- No
Replace A/C control.