1993 CHEVROLET DYNASTY oil

AP BODY INDEX
page page
Cluster and Gauge Service and Testing ....... 58
Gauges ................................ 61
General Information ....................... 58 Instrument Panel Replacement
.............. 72
Interior Lamp Replacement ................. 73
Switch and Panel Component Service ......... 67
GENERAL INFORMATION
INSTRUMENT CLUSTER
There are two conventional instrument cluster as-
semblies available. The clusters incorporates mag-
netic type gauges and an electronically driven
speedometer and odometer assembly (Fig. 1 and 2).
MAGNETIC GAUGES
All gauges on the AP Body clusters are the mag-
netic type gauges. When the ignition switch is in the
OFF position each gauge, except for the voltmeter
and tachometer will show a reading. However, the
readings are only accurate when the ignition switch
is in the ON position.
TACHOMETER DRIVE MODULE
The tachometer drive module is an electronic mod-
ule used to drive the magnetic tachometer in the
high line cluster. This module is located on top of the instrument
cluster.
ELECTRONIC DIGITAL CLOCK
The electronic digital clock is in the radio. The
clock and radio each use the display panel built into
the radio. A digital readout indicates the time in
hours and minutes whenever the ignition switch is in
the ON or ACC position. When the ignition switch is in the OFF position, or
when the radio frequency is being displayed, time
keeping is accurately maintained. The procedure for setting the clock varies slightly
with each radio. The correct procedure is described
under the individual radio operating instructions re-
fer to the Sound Systems Manual supplied with the
vehicle.
WARNING LAMPS AND INDICATOR LIGHTS
The instrument cluster has warning and indicators
lamps for eight different systems:
² Low oil pressure
² Brake warning
² Seat belt warning
² Malfunction indicator (check engine) lamp
² Air Bag
² High beam indicator
² Right and left turn signals.
² Anti-lock (ABS)
CLUSTER AND GAUGE SERVICE AND TESTING
CAUTION: Disconnect the negative battery cable
before servicing the instrument panel. When power
is required for test purposes, reconnect battery ca-
ble for test only. Disconnect the negative battery
cable after test and before continuing service pro-
cedures.
SENDING UNIT TEST
Check for a defective sending unit or wiring, when
a problem occurs with a cluster gauge. Do this before
disassembling the cluster. (1) Sending units and wiring can be checked by
grounding the connector leads, at the sending unit,
in the vehicle. (2) With the ignition in the ON position, a
grounded input will cause the fuel or temperature
gauge to read at or above maximum.
Fig. 1 Instrument Cluster With Tachometer
Fig. 2 Instrument Cluster Without Tachometer
8E - 58 INSTRUMENT PANEL AND GAUGES Ä

FUEL TANK SENDING UNIT TEST
Refer to Group 14, Fuel for test procedures.
LOW OIL PRESSURE WARNING LAMP TEST
The low oil pressure warning lamp will illuminate
when the ignition key is turned to the ON position
without engine running. The lamp also illuminates
should the engine oil pressure drop below a safe oil
pressure level. To test the system turn ignition key to the ON po-
sition. If the lamp fails to light, inspect for a broken
or disconnected wire at the oil pressure combination
unit, located at the front of the engine (Fig. 3). If the
wire at the connector checks good, pull connector
loose from the switch and with a jumper wire ground
connector to the engine. With the ignition key turned
to the ON position check the warning lamp. If lamp
still fails to light, inspect for a burned out lamp or
disconnected socket in the cluster.
COMBINATION OIL SENDING UNIT TEST
The combination oil sending unit has two func-
tions: (1) The normal closed circuit keeps the oil pressure
warning lamp on until there is oil pressure (Fig. 4).
(2) The sending unit provides a resistance that
varies with oil pressure. To test the normally closed oil lamp circuit, discon-
nect the locking connector and measure the resis-
tance between the switch terminal and the metal
housing. The ohmmeter should read continuity. Start
the engine. If there is oil pressure, the ohmmeter should read
an open circuit. To test the sending unit, measure the resistance
between the sending unit terminal and the metal
housing. The ohmmeter should no continuity. Start
the engine. The ohmmeter should read between 30 to 55 ohms,
depending on engine speed, oil temperature and oil
viscosity. If the above results are not obtained, replace the
sending unit.
SEAT BELT WARNING SYSTEM
For testing of this system refer to Group 8M, Re-
straint Systems.
AIR BAG WARNING SYSTEM
For testing of this system refer to Group 8M, Re-
straint Systems.
MALFUNCTION INDICATOR (CHECK ENGINE) SYSTEM
For testing of this system using DRB II, refer to
the Body Powertrain Diagnostic Procedures.
BRAKE SYSTEM WARNING LAMP TEST
The brake warning lamp illuminates when parking
brake is applied with ignition key turned ON. The
same lamp will also illuminate should one of the two
service brake systems fail when brake pedal is ap-
plied. Refer to Brake system warning Lamp Diagno-
sis (Fig. 5). To test system turn ignition key ON and apply
parking brake. If lamp fails to light, inspect for a
burned out lamp, disconnected socket, a broken or
disconnected wire at switch. The lamp also lights
when the ignition switch is turned to start. To test service brake warning system, raise vehicle
on a hoist and open a wheel cylinder bleeder while a
helper depresses brake pedal and observes warning
lamp. If lamp fails to light, inspect for a burned out
lamp, disconnected socket, a broken or disconnected
wire at switch. If lamp is not burned out and wire continuity is
proven, replace brake warning switch in brake line
Tee fitting mounted on frame rail in engine compart-
ment below master cylinder (Fig. 6).
CAUTION: If wheel cylinder bleeder was opened
check master cylinder fluid level.
Fig. 3 Combination Oil Sending Unit
Fig. 4 Combination Oil Sending Unit Test
Ä INSTRUMENT PANEL AND GAUGES 8E - 59

(5) Reconnect battery.
GAUGES
CAUTION: During the removal and installation
watch overlays are not damage.
It is not necessary to remove instrument cluster
from vehicle for gauge replacement. When removing gauge assemblies from cluster,
gauge must be pulled straight out, not twisted, or
damage to gauge pins may result.
MULTIPLE GAUGE INOPERATIVE
Volt, speedometer, tachometer and other gauges
appear to malfunction. Also check warning indicator
lamps: (1) Remove cluster
(2) Check for ignition voltage at pin E of the red
connector. If no voltage, repair as necessary (Fig. 8). (3) Check for ground continuity between pin C of
the gray connector. If no ground, repair as necessary. (4) If voltage and ground OK and pins or connec-
tors are not distorted, replace printed circuit board. (5) Install cluster.
SINGLE GAUGE INOPERATIVE (FIG. 9 AND10)
(1) Remove gauge in question. (2) With the ignition key ON, check for ignition
voltage at ignition pin of gauge. Check for ground at
ground pin of gauge. (a) If no voltage or ground, remove cluster and
check pin E red connector for ignition voltage or
pin C gray connector for ground (Fig. 8). (b) If no voltage or ground, repair as necessary.
Refer to 8W, Wiring Diagrams. (c) If there is voltage or ground, check cluster for
distorted terminals. If terminals are OK, replace
printed circuit board.
(3) When testing the temperature gauge, allow the
engine to run until the vehicle reaches a normal op-
erating temperature. Turn ignition OFF and remove
gauge from cluster.
² When checking the temperature and oil pressure
gauges, it is important to have the same engine tem-
perature and engine speed when noting gauge posi-
tion.
² The time between gauge position reading and
sending unit measuring should be kept to a mini-
mum.
² When testing oil pressure gauge, engine needs to
be running. (a) Measure and record the resistance between
sending unit pin and ground pin of the gauge in
question. Refer to Gauge Calibration.
Fig. 7 Upper Instrument Panel Components
Ä INSTRUMENT PANEL AND GAUGES 8E - 61

(f) If everything checks out OK, refer to Sending
Unit Test.
(4) With the ignition switch in the ON position,
check for battery voltage across the ignition pin and
the ground pin. (5) If fuel gauge meets specifications check fuel
tank and original fuel tank sending unit as follows: (a) Carefully remove fuel tank sending unit from
tank. (b) Refer to sending unit removal Group 14,
Fuel. (c) Connect sending unit wire and jumper wire
as described in the test procedure.
(6) If fuel gauge now checks within specifications,
original sending unit is electrically okay, check fol-
lowing as a possible cause: (a) Ground wire from sending unit to left side
cowl for continuity. (b) Sending unit deformed. Make sure sending
unit float arm moves freely and pick up tube is not
bent upwards creating an interference with bottom
of tank and inspect float. (c) Sending unit improperly installed. Install
properly. (d) Mounting flange on fuel tank for sending
unit deformed. Feel for interference fit of sending
unit to bottom of tank. It is permissible to bend
pick up tube down a little near mounting flange to
gain interference fit. (e) Fuel tank bottom deformed, causing improper
positioning of sending unit pick up tube. Replace or
repair tank and recheck sending unit.GAUGE CALIBRATION
(1) Remove the gauge.
(2) Check for ignition voltage and ground to the
gauge. (3) With the ignition key in the OFF position, re-
place gauge. Turn the ignition key to the ON posi-
tion. To test oil pressure gauge engine must be
running. When testing oil or temperature gauge the
engine should be at normal operating temperature.
Record the gauge position. (4) Remove gauge and record the resistance be-
tween the sending unit pin and the gauge ground
pin. When checking gauges, it is important to have
the same engine temperature and speed when noting
gauge position. The time between gauge reading and
measuring should be kept to a minimum. (5) Resistance Chart (Fig. 11), is general guide-
lines for checking the gauge position against the
sending unit resistance. Because of only a few specific points of gauge posi-
tion versus sending unit resistance, a good estimate
is needed when the resistance falls between gradua-
tions. Even when the resistance corresponds to grad-
uations, the gauge has a tolerance of 64 ohms.
Volt gauge: The calibration dot on the volt gauge
corresponds to 13 volts between the gauge ignition
and ground pins. If voltage varies from this, estimate
proper gauge position with input voltage.
FUEL GAUGE REPLACEMENT
(1) Remove instrument cluster bezel.
(2) Remove mask and lens.
(3) If equipped with tachometer, remove three re-
taining screws and pull the tach straight back.
Fig. 10 Instrument Cluster Without Tachometer
Ä INSTRUMENT PANEL AND GAUGES 8E - 63

LAMPS
CONTENTS
page page
BULB APPLICATION TABLE ............... 38
CONCEALED HEADLAMPS ................ 27
EXTERIOR LAMP SWITCHES AND HEADLAMP ALIGNMENT ........................... 3
EXTERIOR LAMP SYSTEMS .............. 25
EXTERIOR LAMPSÐAA BODY ............. 7
EXTERIOR LAMPSÐAC BODY ............ 10 EXTERIOR LAMPSÐAG BODY
............ 14
EXTERIOR LAMPSÐAJ BODY ............ 16
EXTERIOR LAMPSÐAP BODY ............ 19
EXTERIOR LAMPSÐAY-BODY ............ 22
GENERAL INFORMATION .................. 1
ILLUMINATED ENTRY SYSTEM ........... 33
GENERAL INFORMATION
Each vehicle is equipped with lamps used for illumi-
nating and indicating purposes. A circuit must have a
good ground to be complete. Circuit ground occurs
when the lamp socket makes contact with the metal
body. On vehicles with plastic lamps, a wire between
the socket and the body makes the grounds. When changing lamp bulbs, check the socket for
corrosion. If corrosion is present, clean contacts with a
wire brush and coat the inside of the socket with
Mopar tMulti-purpose Grease or equivalent.
CAUTION: Do not touch the glass of halogen bulbs
with fingers or any possibly oily surface, reduced
bulb life will result.
BODY IDENTIFICATION
Throughout this Group, references are made to the
vehicle family or body code. To decode the vehicle
identification plates, refer to the Introduction Section
at the front of this manual.
DIAGNOSTIC PROCEDURES
Begin electrical system failure diagnosis by testing
all related fuses and circuit breakers in the fuse block
and engine compartment. When a vehicle experiences problems with the head-
lamp system, verify the condition of the battery con-
nections, charging system, headlamp bulbs, wire con-
nectors, relay, high beam dimmer switch and headlamp
switch. Refer to Wiring Diagrams manual for compo-
nent locations and circuit information.
SYMPTOM
Headlamps are dim when engine is idling of
with ignition turned OFF. Canada cars must
have lamps ON. ACTION
² Clean battery terminal clamps and posts. Refer to
Group 8B, Battery/Starter/Generator Service for
proper procedures.
² Test charging system output. Refer to Group 8A,
Battery/Starting/Charging Systems Diagnostics for
proper testing procedures.
² Test for high resistance in headlamp circuits.
² Defective headlamp bulb.
SYMPTOM
Bulbs burn out frequently.
ACTION
² Test charging system output. Refer to Group 8A,
Battery/Starting/Charging Systems Diagnostics for
proper testing procedures.
² Check for loose or corroded connector terminals or
splices in headlamp circuits. Refer to Wiring Diagrams
manual for component and splice locations.
SYMPTOM
Headlamps are dim with engine running above
idle. Canada cars must have lamps ON.
ACTION
² Test charging system output. Refer to Group 8A,
Battery/Starting/Charging Systems Diagnostics for
proper testing procedures.
² Test for high resistance in headlamp circuits.
² Defective headlamp bulb.
SYMPTOM
Headlamps flash randomly.
ACTION
² Test for poor circuit ground.
² Test for high resistance in headlamp circuits.
Ä LAMPS 8L - 1

EXTERIOR LAMPSÐAA BODY INDEX
page page
Center High-Mounted Stop Lamp (CHMSL) Bulb . . 9
Fog Lamp ............................... 9
Fog Lamp Bulb ........................... 9
Front Side Marker Lamp or Bulb .............. 7
Headlamp Bulb ........................... 7 Headlamp Lens
........................... 7
License Plate Lamp or BulbÐAA/P Body ....... 8
License Plate LampsÐAA/C Body ............. 8
Park and Turn Signal Lamp or Bulb ........... 7
Tail, Stop and Turn Signal and Back-Up Lamp . . . 8
HEADLAMP BULB
REMOVAL (FIG. 1)
(1) Raise hood to the open position.
(2) Disconnect wire connector from lamp socket be-
hind the headlamp in the engine compartment. (3) Rotate bulb retaining ring counterclockwise
one quarter turn and remove the ring from the lamp. (4) Pull bulb from the lens assembly. When install-
ing bulb, align notches on bulb base to grooves in
lamp opening.
CAUTION: Do not touch the bulb with fingers or any
possibly oily surface, reduced bulb life will result.
INSTALLATION
Reverse the preceding operation.
HEADLAMP LENS
REMOVAL
(1) Raise hood to the open position.
(2) Disconnect wire connector from back of head-
lamp bulb. (3) Remove screws holding side marker lamp to
front fender. (4) Separate side marker lamp from fender and re-
move bulb socket from lamp. (5) Remove screws holding headlamp to radiator
closure panel. (6) Separate headlamp from radiator closure panel.
INSTALLATION
Reverse the preceding operation.
PARK AND TURN SIGNAL LAMP OR BULB
REMOVAL (FIG. 2)
(1) Remove screws holding park and turn signal
lamp to bumper fascia. (2) Separate lamp from bumper fascia.
(3) Remove socket from lamp.
(4) Pull bulb from socket.
INSTALLATION
Reverse the preceding operation.
FRONT SIDE MARKER LAMP OR BULB
REMOVAL (FIG. 3)
(1) Remove lamp assembly attaching screws and
separate the lamp from the front fender opening. (2) Rotate the side marker lamp socket counter-
clockwise one quarter turn and pull the socket and
bulb from the lamp. (3) Remove the bulb from the socket.
Fig. 1 Aero Headlamp
Fig. 2 Park and Turn Signal Lamp
Ä LAMPS 8L - 7

CENTER HIGH-MOUNTED STOP LAMP (CHMSL)
BULB
REMOVAL (FIG. 7)
(1) Pull cover from lamp assembly.
(2) Rotate socket counterclockwise to remove
socket and bulb. (3) Remove bulb from socket.
INSTALLATION
Reverse the preceding operation.
FOG LAMP BULB
REMOVAL (FIG. 8)
(1) From behind front bumper fascia disengage fog
lamp wire connector from bulb base. (2) Rotate bulb base counterclockwise one half
turn and pull bulb from lamp. CAUTION: Do not touch bulb glass with fingers or
other possibly oily surface, reduced bulb life will re-
sult.
INSTALLATION
Reverse the preceding operation.
FOG LAMP
REMOVAL (FIG. 8)
(1) Disengage wire connector.
(2) Remove nut holding lamp mounting bracket.
(3) Pull the lamp assembly from opening in
bumper fascia.
INSTALLATION
Reverse the preceding operation. Refer to Fog
Lamp Adjustment Procedures in this group for align-
ment instructions.
Fig. 7 Center High-Mounted Stop Lamp
Fig. 8 Fog Lamp
Ä LAMPS 8L - 9

EXTERIOR LAMPSÐAC BODY INDEX
page page
Aero Headlamp Bulb ...................... 10
Aero Headlamp Housing ................... 11
Aero HeadlampsÐAC/D-Body ............... 10
Center High Mounted Stop Lamp (CHMSL) ..... 13
Center High-Mounted Stop Lamp (CHMSL) Bulb . 13
Cornering Lamp Assembly .................. 12
Cornering Lamp Bulb ..................... 12
Front Side Marker BulbÐAC/C-Body .......... 12
Front Side Marker LampÐAC/C-Body ......... 12
Headlamp Diagnosis ...................... 10 Headlamp Sealed BeamÐAC/C Body
......... 10
License Plate Lamp/Bulb ................... 13
Park/Turn Signal Lamp or BulbÐAC/C-Body .... 11
Park/Turn Signal Lamp or BulbÐAC/D-Body .... 11
Rear Side Marker Lamp BulbÐAC/C-Body ..... 13
Rear Side Marker LampÐAC/C-Body ......... 13
Tail, Stop, Turn Signal, Back-Up and Side Marker LampÐAC/D-Body ...................... 12
Tail, Stop, Turn Signal, Back-Up LampÐAC/C or AY/S-Body ............................ 12
HEADLAMP DIAGNOSIS
Refer to the Headlamp Diagnosis at the beginning of
this Group. Refer to Wiring Diagrams Manual for
circuit and component locations.
HEADLAMP SEALED BEAMÐAC/C BODY
REMOVAL
(1) Turn the headlight switch ON.
(2) Open the hood and locate the Power Distribution
Center forward of the left front suspension tower (Fig.
1). Remove the cover. (3) Remove the Headlamp Close Relay (Fig. 2) to
prevent the headlamp doors from closing. (4) Turn the headlight switch OFF.
(5) Remove screws from headlamp bezel and remove
bezel, if equipped. (6) Remove screws from interior retaining ring (Fig.
3), and remove ring. Do not disturb the headlamp adjusting screws.
(7) Pull out sealed beam unit and unplug connector.
INSTALLATION
Reverse the preceding operation.
AERO HEADLAMPSÐAC/D-BODY
Lens fogging is a normal condition and does
not require service, as moisture will vent from
tubes behind the lens.
AERO HEADLAMP BULB
REMOVAL (FIG. 4)
(1) Locate and remove the wire connector behind the
headlamp assembly in the engine compartment.
CAUTION: Do not touch the bulb with fingers or any
possibly oily surface, reduced bulb life will result. (2) Rotate the bulb retaining ring counterclockwise
one quarter turn and remove the ring, bulb and bulb
holder from the lens assembly. The bulb holder has
alignment notches.
INSTALLATION
Reverse the preceding operation.
Fig. 1 Power Distribution Center
Fig. 2 Headlamp Close Relay
8L - 10 LAMPS Ä