Dodge Nitro. Manual — part 742

1. Position the blower motor power module (3) into the HVAC housing (1).

2. Install the two screws (2) that secure the blower motor power module to the HVAC housing. Tighten the

screws to 1.2 N.m (10 in. lbs.).

3. Connect the wire harness connectors (4) to the blower motor power module.

4. Close the glove box door.

5. Reconnect the negative battery cable.

RESISTOR-BLOWER MOTOR

DESCRIPTION

RESISTOR-BLOWER MOTOR

Fig. 47: Mounting Plate, Integral Wire Connector Receptacle & Metal Housing
Courtesy of CHRYSLER LLC

A blower motor resistor is used on vehicles equipped with the manual temperature control (MTC) heating-A/C
system. Vehicles equipped with the automatic temperature control (ATC) heating-A/C system use a blower
motor power module, instead of the blower motor resistor. See DESCRIPTION.

The blower motor resistor is mounted to the rear of the HVAC housing, directly behind the glove box. The
blower motor resistor consists of a molded plastic mounting plate (1) with an integral wire connector receptacle
(2). Concealed behind the mounting plate is the resistor circuit board located within a metal housing (3).

The blower motor resistor is accessed for service through the glove box opening.

OPERATION

RESISTOR-BLOWER MOTOR

NOTE:

LHD model shown. RHD model similar.

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Service Information - Nitro

The blower motor resistor is connected to the vehicle electrical system through a dedicated wire lead and
connector of the HVAC wire harness. The blower motor resistor has multiple resistor circuits, each of which
will reduce the current flow through the blower motor to change the blower motor speed.

The blower motor control in the MTC heating-A/C system directs the ground path for the blower motor through
the correct resistor circuit to obtain the selected speed. With the blower motor control in the lowest speed
position, the ground path for the blower motor is applied through all of the resistor circuits. Each higher speed
selected with the blower motor control applies the blower motor ground path through fewer of the resistor
circuits, increasing the blower motor speed. When the blower motor control is in the highest speed position, the
blower motor resistor is bypassed and the blower motor receives a direct path to ground.

The blower motor resistor cannot be adjusted or repaired and it must be replaced if found inoperative or
damaged.

DIAGNOSIS AND TESTING

RESISTOR-BLOWER MOTOR

1. Disconnect and isolate the negative battery cable.

2. Disconnect the wire harness connector from the blower motor resistor. See REMOVAL.

3. Using an ohmmeter, check for continuity between all of the blower motor resistor terminals. In each case

there should be continuity. If OK, repair the wire harness circuits between the blower motor speed control
and the blower motor resistor or blower motor as required. If not OK, replace the inoperative blower
motor resistor.

REMOVAL

RESISTOR-BLOWER MOTOR

WARNING:

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:

For circuit descriptions and diagrams, refer to WIRING DIAGRAM
INFORMATION . The wiring information includes wiring diagrams, proper wire
and connector repair procedures, further details on wire harness routing and
retention, as well as pin-out and location views for the various wire harness
connectors, splices and grounds.

WARNING:

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

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Service Information - Nitro

Fig. 48: Blower Motor Resistor, Wire Harness Connector, Screws & HVAC Housing
Courtesy of CHRYSLER LLC

1. Disconnect and isolate the negative battery cable.

2. Lower the glove box door.

3. Disconnect the wire harness connector (2) from the blower motor resistor (1).

4. Remove the two screws (3) that secure the blower motor resistor to the HVAC housing (4) and remove

the resistor.

INSTALLATION

RESISTOR-BLOWER MOTOR

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.

WARNING:

The blower motor resistor may get very hot during normal operation. If
the blower motor was turned on prior to servicing the blower motor
resistor, wait five minutes to allow the blower motor resistors to cool
before performing diagnosis or service. Failure to take this precaution
can result in possible personal injury.

NOTE:

Typical resistor shown. RHD model similar.

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Service Information - Nitro

Fig. 49: Blower Motor Resistor, Wire Harness Connector, Screws & HVAC Housing
Courtesy of CHRYSLER LLC

1. Position the blower motor resistor (1) into the HVAC housing (4).

2. Install the two screws (3) that secure the blower motor resistor to the HVAC housing. Tighten the screws

to 1.2 N.m (10 in. lbs.).

3. Connect the wire harness connector (2) to the blower motor resistor.

4. Close the glove box door.

5. Reconnect the negative battery cable.

SENSOR-EVAPORATOR TEMPERATURE

DESCRIPTION

SENSOR-EVAPORATOR TEMPERATURE

NOTE:

Typical resistor shown. RHD model similar.

2007 Dodge Nitro R/T

2007 HVAC Heating & Air Conditioning - Service Information - Nitro