Climate Control - Blower Control Service Tips
Article No.00-21-3
10/16/00
CLIMATE CONTROL - EATC - BLOWER MOTOR CONTROL SERVICE TIPS
FORD:
1990-1993 THUNDERBIRD
1990-2001 CROWN VICTORIA
1995-2001 EXPLORER
LINCOLN:
1990-2001 TOWN CAR
2000-2001 LS
MERCURY:
1990-1993 COUGAR
1990-2001 GRAND MARQUIS
1997-2001 MOUNTAINEER
ISSUE
The following service procedure has been developed to aid technicians in diagnosing EATC/DATC system blower motor control concerns.
ACTION
Refer to the following Service Procedure as an aid in helping diagnose blower motor control concerns.
SERVICE PROCEDURE
1. Check blower motor operation in all speeds.
^ If the blower motor does not operate in any speed, refer to Step 2.
^ If the blower motor continuously operates in HIGH, refer to the appropriate pinpoint test in the Service/Workshop Manual.
^ If the blower motor does not operate in HIGH speed, refer to Step 3.
^ If the blower motor does not operate at speeds other than HIGH, refer to Step 4.
NOTE: REFER TO FIGURE 1 FOR CONNECTOR VIEW.
2. Refer to the appropriate pinpoint test in the Service/Workshop Manual, except for checking the EATC/DATC module. When checking the EATC/DATC module, set the blower motor speed to HIGH blower and measure the voltage between the blower motor high blower relay circuit (Pin 3 at the controller) and ground at the EATC/DATC module connector.
a. If the voltage is within 2 volts of battery voltage, measure the resistance between the blower motor speed controller connector Pin 3 and the corresponding circuit/pin at the EATC/DATC module connector. If the resistance is 5 ohms or less, install a new blower motor speed controller (19E624). If the resistance is greater than 5 ohms, repair the circuit. Retest the system for proper operation.
b. If the voltage is more than 2 volts below battery voltage, measure the resistance between the blower motor speed controller connector Pin 3 and ground. If the resistance is 5 ohms or less, repair the circuit. If the resistance is greater than 5 ohms, install a new EATC/DATC module (19980). Retest the system for normal operation.
3. Set the blower speed control to HIGH and measure the voltage between the blower motor control high blower relay circuit (Pin 3 at the controller) and ground at the EATC/DATC module connector.
a. If the voltage is within 2 volts of battery voltage, measure the resistance between the blower motor speed controller connector Pin 3 and the corresponding circuit/pin at the EATC/DATC module connector. If the resistance is 5 ohms or less, install a new blower motor speed controller (19E624). If the resistance is greater than 5 ohms, repair the circuit. Retest the system for proper operation.
b. If the voltage is more than 2 volts below battery voltage, measure the resistance between the blower motor speed controller connector Pin 3 and ground. If the resistance is greater than 5 ohms, install a new EATC/DATC module (19980). If the resistance is 5 ohms or less, repair the circuit. Retest the system for normal operation.
4. Set the blower speed control to any speed other than HIGH and measure the voltage between the blower motor control blower control circuit (Pin 2 at the controller) and ground at the EATC/DATC module.
a. If the voltage is below 1 volt, measure the resistance between the blower motor speed controller connector Pin 1 and ground. If the resistance is greater than 5 ohms, install a new EATC/DATC module (19980). If the resistance is 5 ohms or less, repair the circuit. Retest the system for normal operation.
b. If the voltage is between 1 and 3 volts, measure the resistance of the circuit between the blower motor speed controller connector Pin 2 and the corresponding pin at the EATC/DATC module connector. If the resistance is 5 ohms or less, install a new blower motor speed controller (19E624). If the resistance is greater than 5 ohms, repair the circuit. Retest the system for normal operation.
c. If the voltage is greater than 3 volts, measure the resistance of the circuit between the blower motor speed controller connector Pin 1 and the corresponding pin at the EATC/DATC module connector. If the resistance is 5 ohms or less; install a new blower motor speed controller (19E624). If. the resistance is greater than 5 ohms, repair the circuit. Retest the system for normal operation.
OTHER APPLICABLE ARTICLES: NONE
WARRANTY STATUS: INFORMATION ONLY
OASIS CODES: 208000, 208300, 208999