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Dodge Durango (HB). Manual - part 346

1. Align the base of the bulb with the headlamp bulb

socket (2).

2. Push the bulb straight into the socket until the base

is firmly seated.

3. Align the socket and bulb with the keyed opening

on the back of the front lamp unit housing (1).

4. Insert the socket and bulb into the housing until the

socket is firmly seated.

5. Rotate the socket clockwise about 30 degrees to

lock it into place.

6. Reinstall the front lamp unit onto the front fender.

(Refer to 8 - ELECTRICAL/LAMPS/LIGHTING -
EXTERIOR/FRONT LAMP UNIT - INSTALLATION).

7. Reconnect the battery negative cable.

SWITCH-HEADLAMP

DESCRIPTION

The headlamp switch (1) is located on the instrument
panel, to the left of the steering column. Three differ-
ent switches are used. The standard switch features a
three-position rotary knob (4) for exterior lighting con-
trol and a thumbwheel (2) for panel lamps dimming
and interior lighting control. An optional switch has a
momentary push button (3) added for front fog lamp
control. A second optional switch has the same thum-
bwheel and momentary push button, but has a fourth
position added to the rotary knob for selecting the
optional automatic headlamps feature.

Each of these switches is constructed of molded plas-
tic. The rotary knob is molded plastic and knurled
around its circumference to ease operator control. The
thumbwheel is also plastic and knurled. The optional
front fog lamp push button is plastic with a smooth fin-
ish and an International Control and Display Symbol
icon for “Front Fog Light” applied to it. The switch face
plate is also labeled with graphics and icons to clearly
identify the many functions of the rotary knob and
thumbwheel.

Three screws secure the switch to the back of the cluster bezel through integral mounting flanges that are molded
to each side of the switch housing. The back of the switch housing has an integral connector receptacle containing
terminal pins that connect the switch to the vehicle electrical system through a dedicated take out and connector of
the instrument panel wire harness. A panel dimmer controlled incandescent bulb soldered to the circuit board within
the switch provides back lighting for visibility at night, but is not serviceable. The headlamp switch cannot be
repaired and, if faulty or damaged, it must be replaced.

OPERATION

The headlamp switch uses two resistor multiplexed outputs to control the many functions and features it provides.
The switch receives a clean ground from the ElectroMechanical Instrument Cluster (EMIC) (also sometimes referred
to as the Cab Control Node/CCN) on a headlamp switch return circuit. It then provides outputs to the EMIC on a

LAMPS/LIGHTING - EXTERIOR - SERVICE INFORMATION

8L - 103

headlamp switch signal circuit to control exterior lighting functions, and on a panel lamps dimmer signal circuit to
control panel dimmer and interior lighting functions.

The switch illumination circuit receives a path to ground at all times through the left instrument panel ground circuit.
The illumination level is controlled by a Pulse-Width Modulated (PWM) output received from the EMIC on a head-
lamp switch illumination control circuit. The EMIC controls this output based upon the dimmer signal select mux
input from the headlamp switch.

The headlamp switch operates as follows:

•

Front Fog Lamps Control - For vehicles so equipped, the fog lamp push button on the headlamp switch is
depressed to activate or deactivate the optional front fog lamps. The headlamp switch provides an output to
the EMIC, and the EMIC responds by sending electronic fog lamp switch status messages to the Front Control
Module (FCM) over the Controller Area Network (CAN) data bus. The FCM responds by energizing or de-
energizing the front fog lamp relay in the Power Distribution Center (PDC).

•

Exterior Lighting Control - The rotary knob on the headlamp switch is rotated to a detent position to activate
or deactivate the exterior lighting. The headlamp switch provides an output to the EMIC, and the EMIC
responds by sending electronic exterior lighting switch status messages to the FCM over the CAN data bus.
The FCM responds by energizing or de-energizing the park lamp relay in the PDC and the high or low beam
headlamp circuits. The FCM remembers which headlamp beams were last selected using the multi-function
switch, and energizes those beams by default the next time the headlamps are turned On. If the vehicle is
equipped with optional automatic headlamps and the Auto position is selected, the EMIC also monitors an
input from a sun load sensor on the instrument panel and, based upon the monitored ambient light levels,
responds by automatically sending appropriate messages to the FCM to turn the exterior lighting On or Off
while the ignition switch is in the On position.

•

Interior Lighting Control - The thumbwheel on the headlamp switch is rotated to the dome defeat, dome on,
parade/funeral mode, or one of the six panel dimmer detent positions to control the interior courtesy/dome and
panel lamps. The headlamp switch provides an output to the EMIC, and the EMIC responds by providing the
appropriate interior lighting control outputs through its internal courtesy lamp driver circuits, electronic dimming
level messages to other modules over the CAN data bus, and/or the proper PWM outputs to control dimming
levels through several panel dimmer illumination control driver circuits.

The headlamp switch can be diagnosed using conventional diagnostic tools and methods. However, proper testing
of the multiplexed inputs to and PWM processing of the EMIC requires the use of a diagnostic scan tool. Refer to
the appropriate diagnostic information.

DIAGNOSIS AND TESTING

HEADLAMP SWITCH

WARNING: To avoid personal injury or death, on vehicles equipped with airbags, disable the supplemental
restraint system before attempting any steering wheel, steering column, airbag, occupant classification sys-
tem, seat belt tensioner, impact sensor, or instrument panel component diagnosis or service. Disconnect
and isolate the battery negative (ground) cable, then wait two minutes for the system capacitor to discharge
before performing further diagnosis or service. This is the only sure way to disable the supplemental
restraint system. Failure to take the proper precautions could result in accidental airbag deployment.

8L - 104

LAMPS/LIGHTING - EXTERIOR - SERVICE INFORMATION

1. Remove the cluster bezel from the instrument

panel (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - REMOVAL).

2. Disconnect the wire harness connector from the

back of the headlamp switch.

3. Using an ohmmeter, test the resistance or continu-

ity between the terminals of the switch as shown in
the Headlamp Switch Tests table.

HEADLAMP SWITCH TESTS

SWITCH POSITION (PINS)

RESISTANCE RANGE (OHMS)

AUTO (1 & 3)

4028.0 - 4457.0

OFF (1 & 3)

1938.0 - 2147.0

PARK (1 & 3)

1073.0 - 1191.5

HEADLAMP (1 & 3)

627.0 - 698.0

FOG LAMP - AUTO (1 & 3)

347.2 - 388.8

FOG LAMP - OFF (1 & 3)

317.7 - 356.1

FOG LAMP - PARK (1 & 3)

280.7 - 315.2

FOG LAMP - HEADLAMP (1 & 3)

236.6 - 266.5

DOME DEFEAT (2 & 3)

14143.6 - 15610.4

PANEL DIMMER 1 (2 & 3)

5498.6 - 6055.4

PANEL DIMMER 2 (2 & 3)

2933.6 - 3220.4

PANEL DIMMER 3 (2 & 3)

1793.6 - 1960.4

PANEL DIMMER 4 (2 & 3)

1147.6 - 1246.4

PANEL DIMMER 5 (2 & 3)

739.1 - 794.9

PANEL DIMMER 6 (2 & 3)

482.6 - 511.4

PARADE/FUNERAL MODE (2 & 3)

301.9 - 327.1

DOME ON (2 & 3)

166.3 - 188.8

SWITCH ILLUMINATION (4 & 5)

CONTINUITY AT ALL TIMES

4. If the switch fails any of the tests, replace the faulty headlamp switch as required.

REMOVAL

LAMPS/LIGHTING - EXTERIOR - SERVICE INFORMATION

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1. Disconnect and isolate the battery negative cable.

2. Remove the cluster bezel (1) from the instrument

panel (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - REMOVAL).

3. Disconnect the wire harness connector from the

back of the headlamp switch (2).

4. Remove the three screws (3) that secure the head-

lamp switch to the back of the cluster bezel.

5. Remove the headlamp switch from the cluster

bezel.

INSTALLATION

1. Position the headlamp switch (2) to the back of the

cluster bezel (1).

2. Install and tighten the three screws (3) that secure

the headlamp switch to the cluster bezel. Tighten
the screws to 2 N·m (17 in. lbs.).

3. Reconnect the wire harness connector to the back

of the headlamp switch.

4. Reinstall the cluster bezel onto the instrument

panel. (Refer to 23 - BODY/INSTRUMENT PANEL/
CLUSTER BEZEL - INSTALLATION).

5. Reconnect the battery negative cable.

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LAMPS/LIGHTING - EXTERIOR - SERVICE INFORMATION

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