brakes. The secondary outlet port supplies hydraulic
pressure to the left front and right rear brakes.
POWER BRAKE VACUUM BOOSTER OPERATION
All vehicles use a 270 mm single diaphragm power
brake vacuum booster.
The power brake booster can be identified if
required, by the tag attached to the body of the
booster assembly (Fig. 10). This tag contains the fol-
lowing information: The production part number of
the power booster assembly, the date it was built,
and who was the manufacturer of the power brake
vacuum booster.
NOTE: The power brake booster assembly is not a
repairable component and must be replaced as a
complete assembly if it is found to be faulty in any
way. The check valve located in the power brake
booster (Fig. 10) is not repairable but it can be
replaced as an assembly separate from the power
brake booster.
The power brake booster reduces the amount of
force required by the driver to obtain the necessary
hydraulic pressure to stop vehicle.
The power brake booster is vacuum operated. The
vacuum is supplied from the intake manifold on the
engine through the power brake booster check valve
(Fig. 10) and (Fig. 11).
As the brake pedal is depressed, the power brake
boosters input rod moves forward (Fig. 11). This
opens and closes valves in the power booster, allow-
ing atmospheric pressure to enter on one side of a
diaphragm. Engine vacuum is always present on the
other side. This difference in pressure forces the out-
put rod of the power booster (Fig. 11) out against the
primary piston of the master cylinder. As the pistons
in the master cylinder move forward this creates the
hydraulic pressure in the brake system.The different engine combinations used on this
vehicle require that different vacuum hose routings
to the power brake vacuum booster be used.
All vacuum hoses must be routed from the engine
to the power brake vacuum booster without kinks,
excessively tight bends or potential for damage to the
vacuum hose.
The power brake vacuum booster assembly mounts
on the engine side of the dash panel, and is con-
nected to the brake pedal by the input push rod (Fig.
11). A vacuum line connects the power booster to the
intake manifold. The master cylinder is bolted to the
front of the power brake vacuum booster assembly.
RED BRAKE WARNING LAMP OPERATION
The red Brake warning lamp is located in the
instrument panel cluster and is used to indicate a
low brake fluid condition or that the parking brake is
applied. In addition, the brake warning lamp is
turned on as a bulb check by the ignition switch
every time the ignition switch is turned to the crank
position.
The warning lamp bulb is supplied a 12 volt igni-
tion feed anytime the ignition switch is on. The bulb
is then illuminated by completing the ground circuit
either through the park brake switch, the fluid level
sensor in the master cylinder reservoir, or the igni-
tion switch when it is turned to the crank position.
The Brake Fluid Level sensor is located in the
brake fluid reservoir of the master cylinder assembly.
The purpose of the sensor is to provide the driver
with an early warning that brake fluid level in the
master cylinder fluid reservoir has dropped to below
Fig. 10 Power Brake Booster Identification
Fig. 11 Power Brake Booster Assembly
5 - 8 BRAKESNS
DESCRIPTION AND OPERATION (Continued)
BER GLOVES, NOT THE HOUSEHOLD TYPE,
SHOULD BE WORN WHEN REMOVING OR SER-
VICING A BATTERY. SAFETY GLASSES ALSO
SHOULD BE WORN.
DESCRIPTION AND OPERATION
BATTERY IGNITION OFF DRAW (IOD)
A completely normal vehicle will have a small
amount of current drain on the battery with the key
out of the ignition. It can range from 5 to 25 milli-
amperes after all the modules time out. If a vehicle
will not be operated for approximately a 20 days, the
IOD fuse should be pulled to eliminate the vehicle
electrical drain on the battery. The IOD fuse is
located in the Power Distribution Center (PDC).
Refer to the PDC cover for proper fuse.
CHARGING TIME REQUIRED
WARNING: NEVER EXCEED 20 AMPS WHEN
CHARGING A COLD -1ÉC (30ÉF) BATTERY. PER-
SONAL INJURY MAY RESULT.
The time required to charge a battery will vary
depending upon the following factors.
SIZE OF BATTERY
A completely discharged large heavy-duty battery
may require more recharging time than a completely
discharged small capacity battery, refer to (Fig. 2) for
charging times.
TEMPERATURE
A longer time will be needed to charge a battery at
-18ÉC (0ÉF) than at 27ÉC (80ÉF). When a fast charger
is connected to a cold battery, current accepted by
battery will be very low at first. In time, the battery
will accept a higher rate as battery temperature
warms.
CHARGER CAPACITY
A charger which can supply only five amperes will
require a much longer period of charging than a
charger that can supply 20 amperes or more.
STATE OF CHARGE
A completely discharged battery requires more
charging time than a partially charged battery. Elec-
trolyte is nearly pure water in a completely dis-
charged battery. At first, the charging current
amperage will be low. As water is converted back to
sulfuric acid inside the battery, the current amp rate
will rise. Also, the specific gravity of the electrolyte
will rise. The electrolyte should be tested with a
Hydrometer to check the specific gravity.
USING HYDROMETER
Before performing a hydrometer test, remove the
battery caps and check the electrolyte level. Add dis-
tilled water as required.
NOTE: Periodically disassemble the hydrometer
and wash components with soap and water. Inspect
the float for possible leaks. If the paper inside has
turned brown, the float is defective.
Before testing, visually inspect the battery for any
damage:
²Cracked container or cover
²Loose post
²Corrosion
and any other thing that would cause the battery
to be unserviceable. To interpret the hydrometer cor-
rectly, hold it with the top surface of the electrolyte
in the hydrometer at eye level.
Disregard the curvature of the liquid where the
surface rises against the float because of surface
cohesion (Fig. 3). Remove only enough electrolyte
from the battery to keep the float off the bottom of
the hydrometer barrel with pressure on the bulb
released. Keep the hydrometer in a vertical position
while drawing the electrolyte into the hydrometer
and observing the specific gravity. Exercise care
when inserting the tip of the hydrometer into a cell
to avoid damage to the separators. Damaged separa-
tors can cause premature battery failure.
Hydrometer floats are generally calibrated to indi-
cate the specific gravity correctly only at one fixed
temperature, 20ÉC (68ÉF). When testing the specific
gravity at any other temperature, a correction factor
is required, otherwise specific gravity readings will
not indicate the true state of charge.
The correction factor is approximately a specific
gravity value of 0.004, referred to as 4 points of spe-
cific gravity for every 5.5ÉC (10ÉF). If electrolyte tem-
perature is below 20ÉC (68ÉF) you subtract. If the
temperature is above 20ÉC (68ÉF) you add to the
Fig. 2 Battery Charging Time
8A - 2 BATTERYNS/GS
GENERAL INFORMATION (Continued)
(2) Insert the trim stick (special tool #C-4755)
between access cover and radio bezel, above conve-
nience bin - cup holder.
(3) Carefully pry the access cover from the instru-
ment panel (Fig. 5).
(4) Separate the access cover from the vehicle.
(5) Using needle-nose pliers, carefully squeeze the
vertical metal legs of the lamp hood.
(6) Lift the lamp hood upward from the cup holder
tray.
(7) Carefully pull the lamp and wiring rearward
from the instrument panel (Fig. 6).
(8) Pull the lamp hood from the lamp socket.
(9) Pull bulb from socket.
INSTALLATION
For installation, for reverse the above procedures.
CONVENIENCE BIN TRACK
REMOVAL
(1) Remove the convenience bin - cup holder. Refer
to Convenience Bin - Cup Holder Removal and
Installation procedure in this section.
(2) Remove the screw access cover from the bottom
of the radio bezel (Fig. 5).(3) Remove the center bezel.
(4) Remove the convenience bin track attaching
screws and pull the convenience bin track rearward
to disengage the rear guide studs from instrument
panel (Fig. 7).
(5) Disengage the clip holding convenience bin
lamp to track.
(6) Remove the convenience bin track.
INSTALLATION
For installation, reverse the above procedures.
BODY CONTROL MODULE (BCM)
REMOVAL
(1) Disconnect battery negative cable.
(2) Remove lower steering column cover and knee
blocker reinforcement.
Fig. 4 Unused Convenience Bin Lamp Socket
Location
Fig. 5 Convenience Bin Access Cover
Fig. 6 Convenience Bin Lamp Bulb
Fig. 7 Convenience Bin Track
8E - 18 INSTRUMENT PANEL AND SYSTEMSNS
REMOVAL AND INSTALLATION (Continued)
HEADLAMP SWITCH LAMP(S)
REMOVAL
(1) Remove instrument cluster bezel.
(2) Disconnect wire connectors.
(3) Remove headlamp switch bezel from instru-
ment cluster bezel.
(4) Rotate bulb socket counterclockwise one quar-
ter turn (Fig. 14).
(5) Pull bulb socket from headlamp switch.
INSTALLATION
For installation, reverse the above procedures.
HVAC CONTROL LAMP
REMOVAL
(1) Remove radio bezel and HVAC Control (Fig.
15).
(2) Remove rear cover from HVAC control.
(3) Rotate bulb socket counterclockwise one quar-
ter turn.
(4) Pull bulb socket from HVAC.
INSTALLATION
For installation, reverse the above procedures.
INSTRUMENT CLUSTER BACK PANEL
REMOVAL
(1) Remove instrument cluster.
(2) Remove screws holding back panel to instru-
ment cluster (Fig. 16).
(3) Remove back panel.
INSTALLATION
For installation, reverse the above procedures.
INSTRUMENT CLUSTER BEZEL
REMOVAL
(1) Remove steering column cover.
(2) Remove over steering column bezel (Fig. 17).
(3) Remove left end cover.
(4) Remove screw at left end of cluster bezel and
headlamp switch.
Fig. 14 Headlamp Switch Lamp
Fig. 15 HVAC Control Lamps
Fig. 16 Instrument Cluster Back Panel
Fig. 17 Instrument Cluster Bezel
NSINSTRUMENT PANEL AND SYSTEMS 8E - 21
REMOVAL AND INSTALLATION (Continued)
with traction control switch connect the wire pigtail
before engaging clips.
(2) Install the screws to hold the over steering col-
umn bezel to the cluster bezel.
(3) Install the lower column cover.
POWER MIRROR SWITCH
REMOVAL
(1) Remove instrument cluster bezel (Fig. 52).
(2) Disconnect wire connector from back of power
mirror switch.
(3) Disengage lock tabs above and below the mir-
ror switch.
(4) Pull power mirror switch from headlamp
switch bezel.
(5) Remove power mirror switch.
INSTALLATION
For installation, reverse the above procedures.
POWER MIRROR SWITCH LAMP
REMOVAL
(1) Remove instrument cluster bezel (Fig. 53).
(2) Rotate bulb socket counterclockwise one quar-
ter turn.
(3) Pull bulb socket from back of power mirror
switch.
INSTALLATION
For installation, reverse the above procedures.
RADIO BEZEL AND HVAC CONTROL
REMOVAL
(1) Remove convenience bin - cup holder. Refer to
Convenience Bin - Cup Holder Removal and Installa-
tion procedure in this section.(2) Insert the trim stick (special tool #C-4755)
between access cover and radio bezel, above conve-
nience bin - cup holder.
(3) Carefully pry the access cover from the instru-
ment panel (Fig. 54).
(4) Separate the access cover from the vehicle.
(5) Remove convenience bin - cup holder track.
Refer to Convenience Bin - Cup Holder Track
Removal and Installation procedures in this section.
(6) Remove the attaching screws holding bottom of
the bezel to instrument panel (Fig. 55).
(7) Remove the attaching screws holding top of the
bezel to the instrument panel.
(8) Remove the bezel from the instrument panel.
(9) Disconnect the wire connector from back of the
rear blower switch, if equipped.
(10) Disconnect the wire connector from the back
of the HVAC Control.
(11) Remove the bezel.
Fig. 52 Power Mirror Switch
Fig. 53 Power Mirror Switch Lamp
Fig. 54 Convenience Bin Access Cover
8E - 34 INSTRUMENT PANEL AND SYSTEMSNS
REMOVAL AND INSTALLATION (Continued)
INSTALLATION
(1) Hold the radio bezel up and connect the wire
connector into the back of the HVAC control.
(2) Connect the wire connector into back of the
rear blower switch, if equipped.
(3) Place the radio bezel in position on the instru-
ment panel.
(4) Install screws to hold the top of radio bezel to
instrument panel.
(5) Install screws to the hold bottom of the radio
bezel to the instrument panel.
(6) Install the access cover.
REAR HEATER-A/C SWITCH
REMOVAL
(1) Remove radio bezel and HVAC Control (Fig.
56).
(2) Remove screw holding rear heater-A/C switch
to radio bezel HVAC Control.
(3) Disengage hook holding bottom of switch to
radio bezel HVAC Control.
(4) Remove switch from radio bezel HVAC Control.
INSTALLATION
For instrument, reverse the above procedures.
REAR HEATER-A/C SWITCH LAMP
REMOVAL
(1) Remove radio bezel HVAC Control.(2) Rotate bulb socket counterclockwise one quar-
ter (Fig. 57).
(3) Pull bulb socket from switch.
INSTALLATION
For installation, reverse the above procedures.
TRACTION CONTROL SWITCH
REMOVAL
(1) Remove the over steering column bezel (Fig.
51). Refer to Over Steering Column Bezel Removal
procedure.
(2) Remove the two screws attaching traction con-
trol switch to the bezel.
INSTALLATION
For installation, reverse the above procedure.
Fig. 55 Radio Bezel and HVAC Control
Fig. 56 Rear Heater ± A/C Switch
Fig. 57 Rear Heater-A/C Switch Lamp Bulb
NSINSTRUMENT PANEL AND SYSTEMS 8E - 35
REMOVAL AND INSTALLATION (Continued)
HEADLAMP SWITCH
REMOVAL
(1) Remove instrument cluster bezel (Fig. 14).
(2) Remove screws holding the headlamp switch
bezel to cluster bezel.
(3) Disconnect the wire connectors from the head-
lamp switch and wire connector from the power mir-
ror switch.
(4) Remove headlamp switch bezel from cluster
bezel.
INSTALLATION
For installation, reverse the above procedures.
HEADLAMP SWITCH LAMP(S)
REMOVAL
(1) Remove instrument cluster bezel.
(2) Disconnect wire connectors.
(3) Remove headlamp switch bezel from instru-
ment cluster bezel.
(4) Rotate bulb socket counterclockwise one quar-
ter turn (Fig. 15).
(5) Pull bulb socket from headlamp switch.
INSTALLATION
For installation, reverse the above procedures.
HVAC CONTROL LAMP
REMOVAL
(1) Remove radio bezel and HVAC Control (Fig.
16).
(2) Remove rear cover from HVAC control.
(3) Rotate bulb socket counterclockwise one quar-
ter turn.
(4) Pull bulb socket from HVAC.
INSTALLATION
For installation, reverse the above procedures.
INSTRUMENT CLUSTER BACK PANEL
REMOVAL
(1) Remove instrument cluster.
(2) Remove screws holding back panel to instru-
ment cluster (Fig. 17).
(3) Remove back panel.
INSTALLATION
For installation, reverse the above procedures.
INSTRUMENT CLUSTER BEZEL
REMOVAL
(1) Remove steering column cover.
(2) Remove over steering column bezel (Fig. 18).
(3) Remove left end cover.
(4) Remove screw at left end of cluster bezel and
headlamp switch.
Fig. 14 Headlamp Switch
Fig. 15 Headlamp Switch Lamp
Fig. 16 HVAC Control Lamps
8E - 18 INSTRUMENT PANEL AND SYSTEMSNS/GS
REMOVAL AND INSTALLATION (Continued)
INSTALLATION
(1) Place message center in position on top cover.
(2) Install screws to hold message center to instru-
ment panel top cover.
(3) Connect wire connector into back of message
center.
(4) Install instrument panel top cover.
(5) Install A-pillar trim.
OVER STEERING COLUMN BEZEL
REMOVAL
(1) Remove the lower steering column cover.
(2) Remove the screws holding over steering col-
umn bezel to the cluster bezel (Fig. 45).
(3) Remove over steering column bezel from vehi-
cle.
(4) Disconnect the clips holding over column bezel
to the cluster bezel.
(5) If equipped with traction control switch, discon-
nect the wire pigtail connector from the traction con-
trol switch.
(6) Remove the over steering column bezel.
INSTALLATION
(1) Place the over steering column bezel in position
and engage clips to the cluster bezel. If equipped
with traction control switch connect the wire pigtail
before engaging clips.
(2) Install the screws to hold the over steering col-
umn bezel to the cluster bezel.
(3) Install the lower column cover.
POWER MIRROR SWITCH
REMOVAL
(1) Remove instrument cluster bezel (Fig. 46).
(2) Disconnect wire connector from back of power
mirror switch.
(3) Disengage lock tabs above and below the mir-
ror switch.
(4) Pull power mirror switch from headlamp
switch bezel.
(5) Remove power mirror switch.
INSTALLATION
For installation, reverse the above procedures.
POWER MIRROR SWITCH LAMP
REMOVAL
(1) Remove instrument cluster bezel (Fig. 47).
(2) Rotate bulb socket counterclockwise one quar-
ter turn.
(3) Pull bulb socket from back of power mirror
switch.
Fig. 45 Over Steering Column Bezel
Fig. 46 Power Mirror Switch
Fig. 47 Power Mirror Switch Lamp
8E - 28 INSTRUMENT PANEL AND SYSTEMSNS/GS
REMOVAL AND INSTALLATION (Continued)