Symptom Chart

WARNING: This page is about a different car, the 2002 Ford Windstar. However, it is still accessible from the selected car via links, so may be relevant.

CLIMATE CONTROL SYSTEM PROBLEM SYMPTOM AND POSSIBLE SOURCES

Condition	Possible Sources	Action
No communication with the front electronics module (FEM) - unable to carry out the front electronics module (FEM) self-test	Fuse. Low battery voltage. Open ground circuit.	Go To PINPOINT TEST A: NO COMMUNICATION WITH THE FRONT ELECTRONIC MODULE (FEM)-UNABLE TO CARRY OUT THE FRONT ELECTRONIC MODULE (FEM) SELF-TEST .
No communication with the rear electronics module (REM) - unable to carry out the rear electronics module (REM) self-test	Fuse. Open ground circuit.	Go To PINPOINT TEST B: NO COMMUNICATION WITH THE REAR ELECTRONIC MODULE (REM)-UNABLE TO CARRY OUT THE REAR ELECTRONIC MODULE (REM) .
No communication with the hybrid electronic instrument cluster (HEC) - unable to carry out the hybrid electronic instrument cluster (HEC) self-test	Low battery voltage at the HEC. Open HEC ground.	Go To PINPOINT TEST C: NO COMMUNICATION WITH THE HYBRID ELECTRONIC INSTRUMENT CLUSTER (HEC) - UNABLE TO CARRY OUT THE HYBRID ELECTRONIC INSTRUMENT CLUSTER (HEC) SELF-TEST .
Incorrect/erratic direction of airflow from outlet	Function selector switch. A/C vacuum check valve. Vacuum hose. A/C vacuum reservoir tank and bracket. Vacuum control motor. Vacuum actuator arm.	Go To PINPOINT TEST D: INCORRECT/ERRATIC DIRECTION OF AIRFLOW FROM OUTLET .
Insufficient, erratic, or no heat	Low engine coolant level. Engine overheating. Plugged or partially plugged heater core. Temperature blend door binding/stuck. A/C electric blend door actuator.	Go To PINPOINT TEST E: INSUFFICIENT, ERRATIC OR NO HEAT .
The A/C does not operate/does not operate correctly	Fuse. Circuitry short/open. A/C cycling switch. A/C system. Function selector switch. A/C refrigerant.	Go To PINPOINT TEST F: THE A/C DOES NOT OPERATE OR DOES NOT OPERATE CORRECTLY .
The A/C is always on	Circuitry short/open. A/C cycling switch. A/C control.	Go To PINPOINT TEST G: THE A/C IS ALWAYS ON .
No operation in all the temperature settings	Temperature blend door. Temperature blend door actuator control. A/C electronic blend door actuator motor. Circuitry short/open.	Go To PINPOINT TEST H: NO OPERATION IN ALL TEMPERATURE SETTINGS .
The blower motor does not operate/does not operate correctly	Fuse. Circuitry short/open. A/C blower motor switch. A/C blower motor resistor. A/C blower motor.	Go To PINPOINT TEST I: THE BLOWER MOTOR DOES NOT OPERATE/DOES NOT OPERATE CORRECTLY .
The blower motor operates continuously in high speed	Circuitry short/open. A/C blower motor resistor. A/C blower motor switch.	Go To PINPOINT TEST J: THE BLOWER MOTOR OPERATES CONTINUOUSLY IN HIGH SPEED .
No operation in high blower setting	A/C open circuit. A/C blower motor switch.	Go To PINPOINT TEST K: NO OPERATION IN HIGH BLOWER SETTING .
No operation in low blower setting	A/C open circuit. A/C blower motor resistor. A/C blower motor switch.	Go To PINPOINT TEST L: NO OPERATION IN LOWER SPEEDS .
The auxiliary blower motor is inoperative	Fuse. Circuitry short/open. Auxiliary blower motor resistor. Auxiliary blower motor.	Go To PINPOINT TEST M: THE AUXILIARY BLOWER MOTOR IS INOPERATIVE .
The auxiliary blower motor does not operate correctly	Fuse. Circuitry short/open. Auxiliary blower motor relay. Auxiliary blower motor speed relay 1. Auxiliary blower motor speed relay 2. Rear auxiliary control. Auxiliary blower motor resistor.	Go To PINPOINT TEST N: THE AUXILIARY BLOWER MOTOR DOES NOT OPERATE CORRECTLY .
The panel/floor controls do not operate using the front/rear auxiliary controls	Low battery reference voltage. Short to ground. Short to battery. Rear air mode actuator. Rear air temperature door actuator. Rear control module.	Go To PINPOINT TEST O: THE PANEL/FLOOR CONTROLS DO NOT OPERATE USING THE FRONT/REAR AUXILIARY CLIMATE CONTROLS .
The temperature controls do not operate using the front/rear auxiliary climate control	Fuse. Auxiliary air temperature door motor. Auxiliary air temperature door. Short to ground. Short to battery.	Go To PINPOINT TEST P: THE TEMPERATURE CONTROLS DO NOT OPERATE USING THE FRONT/REAR AUXILIARY CLIMATE CONTROLS .
The panel/floor and cool/warm controls do not operate using the front/rear auxiliary controls	Circuitry short/open. Auxiliary climate control module.	Go To PINPOINT TEST Q: THE PANEL/FLOOR AND COOL/WARM CONTROLS DO NOT OPERATE USING THE FRONT/REAR AUXILIARY CONTROLS .
The panel/floor and warm/cold control does not operate/does not operate correctly using the rear auxiliary controls	Circuitry short/open. Front/rear auxiliary potentiometer. Auxiliary blend door actuator. Auxiliary climate control module.	Go To PINPOINT TEST R: THE PANEL/FLOOR AND COOL/WARM CONTROLS DO NOT OPERATE/DO NOT OPERATE CORRECTLY WHEN USING THE REAR AUXILIARY CONTROLS .