Controls - Rear: Overview Dodge Durango II

DESCRIPTION

The rear blend door actuator (1) is a reversible, 12 volt direct current (DC), servo motor. The rear blend door actuator is located on the side of the rear HVAC housing. The rear blend door actuator is interchangeable with the actuator for the mode-air door. Each actuator is contained within an identical black molded plastic housing with an integral wire connector receptacle. Three integral mounting tabs allow the actuator to be secured to the rear HVAC housing. Each actuator also has an identical output shaft with splines that connects it to the rear blend-air door. The rear blend door actuator does require mechanical indexing to the rear blend-air door, as it is electronically calibrated by the A/C-heater control.

Scheme 337

OPERATION

The rear blend door actuator is connected to the A/C-heater control through the vehicle electrical system by a dedicated two-wire lead and connector of the rear HVAC wire harness. The rear blend door actuator can move the rear blend-air door 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 rear blend-air door will move in one direction. When the A/C-heater control reverses the polarity of the voltage to the motor, the rear blend-air door moves in the opposite direction.

When the A/C-heater control makes the voltage to both connections high or both connections low, the rear blend-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 rear blend door actuator and the rear blend-air door. The A/C-heater control learns the rear blend-air door stop positions during the calibration procedure and will store a diagnostic trouble code (DTC) for any problems it detects in the rear blend door actuator circuit.

The rear blend door actuator cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.

The rear blend door actuator is diagnosed using a scan tool. Refer to HVAC - ELECTRICAL DIAGNOSTICS for more information.

Scheme 338

1. Disconnect and isolate the negative battery cable.
2. Remove right rear quarter panel trim (Refer to «PANEL-QUARTER TRIM»(/dodge/durango/ii-2003-2006/remont/exteriorinterior-trim/#interior) ).
3. Remove the screws (4) that secure the rear blend door actuator (2) to the side of the rear HVAC housing (3).
4. Disconnect the rear HVAC wire harness connector (1) from the rear blend door actuator.
5. Remove the rear blend door actuator from the rear HVAC housing.

Scheme 339

Scheme 340

1. Position the rear blend door actuator (1) onto the side of the rear HVAC housing (2). If necessary, rotate the actuator slightly to align the splines on the actuator output shaft (3) with those on the rear actuator coupler (4).
2. Install the screws (4) that secure the rear blend door actuator (2) to the rear HVAC housing (3). Tighten the screws to 2 N.m (17 in. lbs.).
3. Connect the rear HVAC wire harness connector (1) to the rear blend door actuator.
4. Install the right rear quarter panel trim (Refer to «PANEL-QUARTER TRIM»(/dodge/durango/ii-2003-2006/remont/exteriorinterior-trim/#interior) ).
5. Reconnect the negative battery cable.
6. Initiate the Actuator Calibration function using a scan tool. Refer to HVAC System Test, found in «HVAC - ELECTRICAL DIAGNOSTICS»(ref-212849) .

The rear mode door actuator (1) is a reversible, 12-volt direct current (DC), servo motor. The rear mode door actuator is located near the front end of the rear HVAC housing. The rear mode door actuator is mechanically connected to the rear mode-air door. The rear mode door actuator is interchangeable with the actuator for the rear blend-air door. Each actuator is contained within an identical black molded plastic housing with an integral wire connector receptacle. Three integral mounting tabs allow the actuator to be secured to the side of the rear HVAC housing. The rear mode door actuator also has an identical output shaft with splines that connects it to the mode-air door. The rear mode door actuator does not require mechanical indexing to the mode-air door, as it is electronically calibrated by the A/C-heater control.

Scheme 341

The rear mode door actuator is connected to the A/C-heater control through the vehicle electrical system by a dedicated two-wire lead and connector of the rear HVAC wire harness. The rear mode door actuator can move the rear model-air door 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 rear mode-air door will move in one direction. When the A/C-heater control reverses the polarity of the voltage to the motor, the rear mode-air door moves in the opposite direction.

When the A/C-heater control makes the voltage to both connections high or both connections low, the rear 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 rear mode door actuator and the rear mode-air door. The A/C-heater control learns the rear mode-air door stop positions during the calibration procedure and will store a diagnostic trouble code (DTC) for any problems it detects in the rear mode door actuator circuit.

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

The rear mode door actuators are diagnosed using a scan tool. Refer to HVAC - ELECTRICAL DIAGNOSTICS for more information.

Scheme 342

1. Disconnect and isolate the negative battery cable.
2. Remove right rear quarter panel trim (Refer to «PANEL-QUARTER TRIM»(/dodge/durango/ii-2003-2006/remont/exteriorinterior-trim/#interior) ).
3. Disconnect the rear HVAC wire harness connector (1) from the rear mode door actuator (2) located on the side of the rear HVAC housing (3).
4. Remove the screws (4) that secure the rear mode door actuator to the rear HVAC housing.
5. Remove the rear mode door actuator from the rear HVAC housing.

Scheme 343

Scheme 344

1. Position the rear mode door actuator (1) onto the side of the rear HVAC housing (2). If necessary, rotate the actuator slightly to align the splines on the actuator output shaft (3) with those in the actuator coupler (4).
2. Install the screws (4) that secure the rear mode door actuator (2) to the rear HVAC housing (3). Tighten the screws to 2 N.m (17 in. lbs.).
3. Connect the rear HVAC wire harness connector (1) to the rear mode door actuator.
4. Reconnect the negative battery cable.
5. Initiate the Actuator Calibration function using a scan tool. Refer to HVAC System Test, found in «HVAC - ELECTRICAL DIAGNOSTICS»(ref-212849) .

The rear A/C-heater control (1) for the rear heater-A/C system is located at the rear of the center floor console and allows intermediate seat passengers to adjust rear temperature and blower motor speed when the front A/C-heater control is set to the Rear position, otherwise the front A/C-heater control operates both the front and the rear heater-A/C systems. The rear A/C-heater control contains

1. a rotary control knob (2) for rear fan speed selection and turning the rear heater-A/C system off.
2. a rotary control knob (3) for rear temperature control.

The rear A/C-heater control cannot be repaired and, if faulty or damaged, it must be replaced. The illumination lamp (4) and the control knobs are available for service replacement.

Scheme 345

With the rear A/C-heater control active, temperature selection dictates the air distribution mode (floor or overhead air) of the rear heater-A/C system. A cool temperature setting directs flow to the overhead outlets and a warm temperature setting to the floor.

The rear A/C-heater control is diagnosed using a scan tool. Refer to HVAC - ELECTRICAL DIAGNOSTICS for more information.

Scheme 346

Scheme 347

1. Disconnect and isolate the negative battery cable.
2. Using a small screwdriver or similar flat blade tool (1), gently push down on the clip retainer (2) located at each top corner of the rear A/C-heater control (3). Rotate the top of rear A/C-heater control downwards to release the two bottom retaining tabs from the slots in the center floor console.
3. Disconnect the wire harness connector (1) from the rear A/C-heater control (2).
4. Remove the rear A/C-heater control from the vehicle.

Scheme 348

Scheme 349

Scheme 350

1. Position the rear A/C-heater control (2) near the center floor console.
2. Connect the wire harness connector (1) to the back of the rear A/C-heater control.
3. Insert the two locator tabs on the bottom of the rear A/C-heater control (1) into the two slots on the bottom edge of the floor console opening (2).
4. Rotate the rear A/C-heater control (3) forward far enough to align the two snap clips on the top of the rear A/C-heater control (4) with the receptacles in the top edge of the floor console opening (5).
5. Using hand pressure, press the top edge of the rear A/C-heater control forward until the two snap clips are fully seated in into the receptacles.
6. Reconnect the negative battery cable.
7. Using a scan tool, calibrate the Rear Temperature Selector potentiometer calibration values.
8. Verify that the Actuator Calibration of the front A/Cheater control has passed. If an Actuator Calibration has not passed correct any errors before proceeding.
9. Rotate the Rear Temperature Selector counter (1) clockwise to the Cold Position, allow the Selector to remain in the Cold Position for 5 seconds.
10. Rotate the Rear Temperature Selector Clockwise to the Hot Position, allow the Selector to remain in the Cold Position for 5 seconds.
11. Calibration is now complete.

The blower motor relay for the rear heating-A/C system is a International Standards Organization (ISO)-type relay. Relays conforming to the ISO specifications have common physical dimensions, current capacities, terminal patterns, and terminal functions. The rear blower motor relay is a electromechanical device that switches battery current from a fuse in the power distribution center (PDC) directly to the rear blower motor. The rear blower motor relay is energized when the relay coil is provided a voltage signal by the ignition switch.

The rear blower motor relay is located in the power distribution center (PDC) in the engine compartment. Refer to the PDC label for rear blower motor relay identification and location.

Scheme 351

The black, molded plastic case is the most visible component of the rear blower motor relay. Five male spade-type terminals extend from the bottom of the base to connect the relay to the vehicle electrical system, and the ISO designation for each terminal is molded into the base adjacent to each terminal. The ISO terminal designations are as follows

1. 30 (Common Feed) - This terminal is connected to the movable contact point of the relay.
2. 85 (Coil Ground) - This terminal is connected to the ground feed side of the relay control coil.
3. 86 (Coil Battery) - This terminal is connected to the battery feed side of the relay control coil.
4. 87 (Normally Open) - This terminal is connected to the normally open fixed contact point of the relay.
5. 87A (Normally Closed) - This terminal is connected to the normally closed fixed contact point of the relay.

The rear blower motor relay is an electromechanical switch that uses a low current input from the ignition switch to control the high current output to the rear blower motor. The movable common feed contact point is held against the fixed normally closed contact point by spring pressure. When the relay coil is energized, an electromagnetic field is produced by the coil windings. This electromagnetic field draws the movable relay contact point away from the fixed normally closed contact point, and holds it against the fixed normally open contact point. When the relay coil is de-energized, spring pressure returns the movable contact point back against the fixed normally closed contact point. The resistor or diode is connected in parallel with the relay coil in the relay, and helps to dissipate voltage spikes and electromagnetic interference that can be generated as the electromagnetic field of the relay coil collapses.

The rear blower motor relay terminals are connected to the vehicle electrical system through a receptacle in the power distribution center (PDC). The inputs and outputs of the rear blower motor relay include

1. The common feed terminal (30) receives a battery current input from a fuse in the PDC through a fused B(+) circuit at all times.
2. The coil ground terminal (85) is connected to a ground at all times.
3. The coil battery terminal (86) receives a battery current input from a fuse in the junction block (JB) through a fused ignition switch output (run) circuit only when the ignition switch is in the On position.
4. The normally open terminal (87) provides a battery current output to the rear blower motor through the rear blower motor relay output circuit only when the rear blower motor relay coil is energized.
5. The normally closed terminal (87A) is not connected to any circuit in this application, but provides a battery current output only when the rear blower motor relay coil is de-energized.

The rear blower motor relay cannot be repaired and, if faulty or damaged, it must be replaced. Refer to SYSTEM WIRING DIAGRAMS for diagnosis and testing of the ISO relay and for complete HVAC wiring diagrams.

Scheme 352

1. Disconnect and isolate the negative battery cable.
2. Locate the power distribution center (PDC) (1).
3. Open the PDC cover (2). NOTE: Refer to the fuse and relay layout map on the inner surface of the PDC cover for rear blower motor relay identification and location.
4. Remove the rear blower motor relay (3) from the PDC.

A rear blower motor resistor block is used on this model when it is equipped with the rear heater-A/C system. The rear blower motor resistor block is mounted to the rear HVAC housing, directly below the rear blower motor. The rear blower motor resistor block consists of a molded plastic mounting plate (1) with an integral wire connector receptacle (2). Concealed behind the mounting plate are coiled resistor wires contained within a ceramic heat sink (3). The rear blower motor resistor block is accessed for service by removing the rear quarter interior trim panel from the right side of the vehicle.

Scheme 353

The blower motor resistor block for the rear heating-A/C system is connected to the vehicle electrical system through a dedicated wire lead and connector of the rear HVAC wire harness. The rear blower motor resistor block has multiple resistor wires, each of which will reduce the current flow through the blower motor to change the blower motor speed.

The blower motor switch in the rear heater-A/C system directs the ground path for the rear blower motor through the correct resistor wire to obtain the selected speed. With the rear blower motor control in the lowest speed position, the ground path for the rear blower motor is applied through all of the resistor wires. Each higher speed selected with the rear blower motor control applies the blower motor ground path through fewer of the resistor wires, increasing the rear blower motor speed.

The rear blower motor resistor block cannot be adjusted or repaired and, if faulty or damaged, it must be replaced.

See also:
• PANEL-QUARTER TRIM