Where is heater/ac blower resistor module - 2004 Mercury Grand Marquis

There are several possible reasons why your blower, vent, defrost, AC, and heater might stop blowing air:

1. Blower Motor Failure: The blower motor is responsible for blowing the air through the vents. If the blower motor fails, you will not get any airflow from the vents.
2. Blower Motor Resistor Failure: The blower motor resistor controls the speed of the blower motor. If the resistor fails, the blower motor may stop working or only work at one speed.
3. Fuse or Relay Failure: A blown fuse or faulty relay in the blower motor circuit can prevent the blower motor from working.
4. Control Module Failure: The HVAC (heating, ventilation, and air conditioning) control module is responsible for controlling the blower motor and other components. If the control module fails, it can prevent the blower motor from working.
5. Vacuum Leak: If your vehicle uses a vacuum system to control the vents, a vacuum leak can prevent the system from working properly.
6. Broken Blend Door: The blend door controls the direction of the airflow. If the blend door breaks or gets stuck, the air may not flow through the correct vents.
7. Wiring or Connector Issues: Faulty wiring or connectors in the blower motor circuit can prevent the blower motor from working.

blower resistor is common to burn causeing smell. check with dealer, there may be a campain on this problem. if not. replace resistor and harness (pig tail) and blower motor..

Check this procedure...Blower Motor Resistor and Controller Replacement


REMOVAL

1. Disconnect and isolate the batten' negative cable.

2. Depress locking tab and unplug the wire harness connector from the blower motor

resistor or controller (power module).

3. Depress locking tab and unplug the resistor or controller connector from the blower

motor.

4. Remove the 2 screws that secure the blower motor resistor or controller to the

heater-AC housing.

5. Remove the blower motor resistor or controller from the heater AC housing.


INSTALLATION

1. Install the blower motor resistor or controller to the heater AC housing. The

housing is indexed to allow (controller power module) mounting in only one

position. Tighten the mounting screws to 2.2 Nm(20 in. Lbs.).

2. Plug in the wire harness connector to the blower motor resistor or controller.

3. Plug in the connector from the blower motor resistor or controller to the blower

motor.

4. Connect the batten' negative cable.




Hope this helps (rerember to rating this and leave a testiomonial).

Welcome to FIxYa.com

Blower Motor Resistor and Controller Replacement

Image Blower Motor Resistor Or Controller/Power Module Remove/Install

REMOVAL

1. Disconnect and isolate the batten' negative cable.

2. Depress locking tab and unplug the wire harness connector from the blower motor

resistor or controller (power module).

3. Depress locking tab and unplug the resistor or controller connector from the blower

motor.

4. Remove the 2 screws that secure the blower motor resistor or controller to the

heater-AC housing.

5. Remove the blower motor resistor or controller from the heater AC housing.

INSTALLATION

1. Install the blower motor resistor or controller to the heater AC housing. The

housing is indexed to allow (controller power module) mounting in only one

position. Tighten the mounting screws to 2.2 Nm(20 in. Lbs.).

2. Plug in the wire harness connector to the blower motor resistor or controller.

3. Plug in the connector from the blower motor resistor or controller to the blower

motor.

4. Connect the batten' negative cable.

Thank you for using FixYa.com

Regards, Lee Davidian

On the passengers side under the dash you will find the blower motor.You might have to remove a panel.By the blower motor there is a blower motor resistor module that gets hot and will melt the connector to the blower motor.Check this area out and if it is melted you need to replace the resistor and the connector.You should be able to get one from the dealership.Hope this helps.Good luck.

The resistor that controls the blower motor. it is a small gadget that has a 2 or 3 wire plug . Replacing the resistor should fix your problem. It is on or near the blower motor. Under the dash. Not easy to remove . But it can be. Please give thumbs up if helped.

Your problem is the Relay which is encased inside the Heater/AC Resistor Module. This is a very common problem with GMC and Chevy Trucks. The Relay's return spring fails and the relay is held closed by gravity. The only fix is to replace the Resistor Module. I have a 2004 Silverado and have replaced the Module 3 times and the Blower Motor twice. The Orange wire feeding the Module is always Hot (12V) and feeds the Relay Contact for Highest Blower Speed. Hence the Blower runs all the time even with the Key off and removed.

Look around on the blower motor box, for some wires going to a connector that is held inside the blower box with a couple of screws. It's the blower motor resistor.

it goes just to the right of the blower motor.

there is no relay for the heater fan it's a 15 amp fuse and is on the accessories circuit. the reostat is responsible for all 3 speeds .with the key off there should be no voltage to the blower motor whether the fans speed fan switch is on or off. the fuse will be located in the fuse paneleither on the drivers left side in the dash or underneath the dash in the fuse block. you have a short in the harness that is under the dash and most likely it's a bad plug on the harness. your going to have to do some searching but that's where the problem short is... please rate