2001 Mercury Marquis Blower motor

CHARLES ALSTATT

MEMBER
2001 MERCURY MARQUIS
V8
2WD
AUTOMATIC
87,000 MILES

The Mercury Grand Marquis has automatic temperature control. There is an itermitting problem with the blower motor. Some time it will run and sometimes it will not. When the car is started if the blower is running it will continue to run as long as the ignition is on. If it does not run it will continue so as long as ignition is on. I have been told I may need a new Electronic Automatic Temerature controll Module. Would this be the problem and if so where is this module located and what would it take to replace it?

1 Reply

BMRFIXIT

MECHANIC
19,053 POSTS

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.
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.
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.
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.