Headlamp Leveling Switch - Jeep KJ 2005 Service Manual

8L - 38 LAMPS/LIGHTING - EXTERIOR
HEADLAMP LEVELING
SWITCH
DESCRIPTION
Fig. 30 Headlamp Leveling Switch
1 - SWITCH
2 - UPPER LATCH FEATURE (1)
3 - CONNECTOR RECEPTACLE
4 - LOWER LATCH FEATURE (2)
5 - THUMBWHEEL
The headlamp leveling switch (Fig. 30) is used only
on vehicles manufactured for certain markets where
the headlamp leveling system is required. The head-
lamp leveling switch is mounted in the driver side
inboard trim bezel on the instrument panel. Only the
switch bezel and thumbwheel are visible on the outer
surface of the instrument panel trim bezel. The black
plastic switch thumbwheel is marked with white
numbers "0," "1," "2," and "3," each of which indicates
one of the four switch detent positions. Each higher
number represents a lower aiming position of the
headlamp beam relative to the road surface.
The black, molded plastic switch housing encloses
the switch thumbwheel mechanism and the leveling
switch circuitry including the switch contacts and a
series resistor configuration. A connector receptacle is
integral to the back of the switch housing, while a
single integral latch feature on the top of the housing
and two latch features on the bottom of the housing
secure the switch in the instrument panel trim bezel.
The switch is connected to the vehicle electrical sys-
tem through a dedicated take out and connector of
the instrument panel wire harness.
The headlamp leveling switch cannot be adjusted
or repaired and, if faulty or damaged, the unit must
be replaced.
OPERATION
The headlamp leveling switch receives battery volt-
age on a fused park lamp relay output circuit from a
fuse in the Junction Block (JB) whenever the park
lamps relay is energized (the park lamps are turned
On). The switch receives a path to ground through a
splice block in the instrument panel wire harness
secured by a nut to a ground stud on the driver side
instrument panel end bracket near the JB.
The only output from the switch is a voltage signal
that it provides to the headlamp leveling motors on a
headlamp adjust signal circuit. Each switch position
selects a different tap on a series resistor within the
switch to provide a different voltage signal to the lev-
eling motors. The higher the switch position number,
the higher the output voltage level.
The headlamp leveling switch can be tested using
conventional diagnostic tools and methods.
DIAGNOSIS AND TESTING

HEADLAMP LEVELING SWITCH

WARNING: To avoid personal injury or death, on
vehicles equipped with airbags, disable the supple-
mental restraint system before attempting any
steering wheel, steering column, airbag, occupant
classification system, seat belt tensioner, impact
sensor, or instrument panel component diagnosis
or service. Disconnect and isolate the battery neg-
ative (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.
(1) Disconnect and isolate the battery negative
cable.
(2) Disconnect the instrument panel wire harness
connector from the headlamp leveling switch.
(3) Using an ohmmeter, perform the resistance
tests at the terminal pins in the headlamp leveling
switch connector receptacle (Fig. 31) as shown in the
Headlamp Leveling Switch Tests table.
HEADLAMP LEVELING SWITCH TESTS
SWITCH POSITION
0
1
2
3
KJ
RESISTANCE (OHMS)
BETWEEN PINS 1 & 3
0.5 ± 0.5
301 ± 1
595 ± 1
739 ± 1