Jeep Grand Cherokee WK. Manual - part 1758

NOTE: The single zone heater-A/C system is equipped with a single blend door actuator. The dual zone
system has two blend door actuators, one for the driver side blend-air door and one for the passenger side
blend-air door.

SINGLE ZONE/DUAL ZONE DRIVER SIDE

1. Disconnect and isolate the negative battery cable.

2. Remove the instrument panel silencer from the

driver side of the instrument panel (Refer to 23 -
BODY/INSTRUMENT

PANEL/INSTRUMENT

PANEL SILENCER - REMOVAL).

3. Remove the three screws (1) that secure the blend

door actuator (2) to the driver side of the HVAC air
distribution housing (3).

4. Remove the blend door actuator from the air distri-

bution housing and disconnect the HVAC wire har-
ness connector (4) from the actuator.

5. Remove the blend door actuator from the vehicle.

DUAL ZONE PASSENGER SIDE

1. Disconnect and isolate the negative battery cable.

2. Remove the glove box from the instrument panel

(Refer

BODY/INSTRUMENT

PANEL/

GLOVE BOX - REMOVAL).

3. Remove the three screws (1) that secure the blend

door actuator (2) to the passenger side of the
HVAC air distribution housing (3).

4. Remove the blend door actuator from the air distri-

bution housing and disconnect the HVAC wire har-
ness connector (4) from the actuator.

5. Remove the blend door actuator from the vehicle.

INSTALLATION

24 - 380

CONTROLS

SINGLE ZONE/DUAL ZONE DRIVER SIDE

1. Position the blend door actuator (1) into the vehi-

cle.

2. Install the blend door actuator onto the driver side

of the HVAC air distribution housing (2). If neces-
sary, rotate the actuator slightly to align the splines
on the actuator output shaft (3) with those on the
blend door cam (4).

3. Install the screws (1) that secure the blend door

actuator (2) to the driver side of the air distribution
housing (3). Tighten the screws to 2 N·m (17 in.
lbs.).

4. Connect the HVAC wire harness connector (4) to

the blend door actuator.

5. Install the instrument panel silencer onto the driver

side of the instrument panel (Refer to 23 - BODY/
INSTRUMENT

PANEL/INSTRUMENT

PANEL

SILENCER - INSTALLATION).

6. Reconnect the negative battery cable.

CONTROLS

24 - 381

DUAL ZONE PASSENGER SIDE

1. Position the blend door actuator (1) into the vehi-

cle.

2. Install the blend door actuator onto the passenger

side of the HVAC air distribution housing (2). If nec-
essary, rotate the actuator slightly to align the
splines on the actuator output shaft (3) with those
on the blend door cam (4).

3. Install the screws (1) that secure the blend door

actuator (2) to the passenger side of the air distri-
bution housing (3). Tighten the screws to 2 N·m (17
in. lbs.).

4. Connect the HVAC wire harness connector (4) to

the blend door actuator.

5. Install the glove box into the instrument panel

(Refer

BODY/INSTRUMENT

PANEL/

GLOVE BOX - INSTALLATION).

6. Reconnect the negative battery cable.

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CONTROLS

ACTUATOR-MODE DOOR

DESCRIPTION

This vehicle uses two mode door actuators (1) which
are reversible, 12-volt direct current (DC), servo
motors. The mode door actuator for the panel/defrost/
demist/floor air doors is located on the driver side end
of the HVAC air distribution housing. The mode door
actuator for the rear floor/console air door is located
on the rear of the air distribution housing near the
front of the floor console area. The mode door actua-
tors are mechanically connected to the mode-air
doors.

The mode door actuator is interchangeable with the
actuators for the blend-air door(s) and the recircula-
tion-air door. Each actuator is contained within an
identical black molded plastic housing with an integral
wire connector receptacle (2). Each actuator also has
an identical output shaft with splines (3) that connects
it to its door linkage and three integral mounting tabs
(4) that allow the actuator to be secured to the HVAC
housing. The mode door actuator does not require
mechanical indexing to the mode-air doors, as it is
electronically calibrated by the A/C-heater control.

OPERATION

The two mode door actuators are connected to the A/C-heater control through the vehicle electrical system by ded-
icated two-wire leads and connectors of the HVAC wire harness. The mode door actuators can move the panel/
defrost/demist/floor air doors in two directions. When the A/C-heater control pulls the voltage on one side of the
motor connection high and the other connection low, the mode-air doors will move in one direction. When the A/C-
heater control reverses the polarity of the voltage to the motor, the mode-air doors moves in the opposite direction.

When the A/C-heater control makes the voltage to both connections high or both connections low, the mode-air door
stops and will not move. The A/C-heater control uses a pulse-count positioning system to monitor the operation and
relative position of the mode door actuators and the mode-air doors. The A/C-heater control learns the mode-air
doors stop positions during the calibration procedure and will store a diagnostic trouble code (DTC) for any prob-
lems it detects in the mode door actuator circuits.

Refer to 24 - HEATING & AIR CONDITIONING - DIAGNOSIS AND TESTING and to 24 - HVAC Electrical Diag-
nostics for more information.

The mode door actuators cannot be adjusted or repaired and, if faulty or damaged, they must be replaced.

REMOVAL

WARNING: On vehicles equipped with airbags, disable the airbag system before attempting any steering
wheel, steering column, or instrument panel component diagnosis or service. Disconnect and isolate the
negative battery (ground) cable, then wait two minutes for the airbag system capacitor to discharge before
performing further diagnosis or service. This is the only sure way to disable the airbag system. Failure to
take the proper precautions could result in accidental airbag deployment and possible personal injury or
death.

NOTE: The heater-A/C system is equipped with two mode door actuators. One for the air doors for the out-
lets in the instrument panel and one for the air door for the rear seat/console outlets.

CONTROLS

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