1999 DODGE RAM instrument cluster

2) Apply voltage to Light Blue/Yellow wire at heated mirror
and ground Black wire at heated mirror. Mirror should become warm to
touch. If mirror is not warm to touch, remove mirror and test wires
for continuity. If no continuity exists, repair wires. If wires are
okay, replace mirror. To test defogger switch, see appropriate wiring
diagram in REAR WINDOW DEFOGGERS article.
NOTE: On Ram Pickup, heated mirror is controlled by mirror defogger
switch.
Ram Pickup
1) Turn ignition on. While watching instrument panel
voltmeter, turn heated mirror switch on. Voltmeter needle should
deflect. With heated mirror on, mirror should be warm to touch after
3-4 minutes. If system operates as described, system is okay at this
time.
2) If system does not operate as described, go to next step.
Illuminated indicator light means only that voltage exists at heated
mirror relay.
3) Ensure ignition is on. Check fuses in Power Distribution
Center (PDC) and junction block. Ensure fuses are fully seated and
connections are secure. If mirrors are still inoperative, problem is
in heated mirror control, mirror heating grid and/or heated mirror
harness or connectors. If turning switch on causes a large deflection
in instrument panel voltmeter, check for a short circuit in system.
Repair as necessary.
REMOVAL & INSTALLATION
CAUTION: When battery is disconnected, vehicle computer and memory
systems may lose memory data. Driveability problems may exist
until computer systems have completed a relearn cycle. See
COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION
before disconnecting battery.
HEATED MIRROR SWITCH
Removal & Installation (Ram Pickup)
Heated mirror switch is part of HVAC control unit. See
appropriate AUTOMATIC A/C-HEATER SYSTEMS article in appropriate AIR
CONDITIONING & HEATING SERVICE & REPAIR section.
POWER MIRROR SWITCH
Removal & Installation (Caravan, Town & Country, & Voyager)
1) Remove cover from over steering column. Remove screws
holding instrument cluster bezel to dash (above cluster lens). Remove
screws holding instrument cluster bezel to dash from each side of
steering column. Disconnect clip holding instrument cluster bezel to
dash from above right vent louver.
2) Separate instrument cluster bezel from dash. Disconnect
wires from back of bezel. Disengage lock tabs above and below mirror
switch. Pull mirror switch from headlight switch bezel. To install,
reverse removal procedure.
Removal & Installation (Dakota & Durango)
1) Pull power mirror switch control knob rearward to remove
it from switch body. Remove nut securing switch to door trim panel.
Pull door latch handle to open position and remove screw securing trim
panel to door. Remove manual window crank handle, if equipped. Release
locking tab on power window/lock switch, if equipped. Remove power
window/lock switch and unplug connector.

Hazard Warning Lights Okay To Front Lights Only
Faulty external bulbs. Faulty contact in turn signal/hazard
switch. Open circuit between hazard switch and turn signal switch.
Open or grounded circuit in wiring to rear lights.
Hazard Warning Lights Okay To Rear Lights Only
Faulty external bulbs. Faulty contact in turn signal/hazard
switch. Open or grounded circuit in wiring to front lights.
Indicator Light Inoperative, External Lights Okay
Burned-out indicator bulb in instrument cluster. Faulty
contact. Open circuit.
Indicator Light Okay, External Lights Inoperative
Open circuit in wiring to external light(s).
Indicator Light Okay, External Lights Glow Dimly Or Do Not
Flash
Loose or corroded external light connections. Poor ground
circuit at external light(s).
Turn Signals Do Not Cancel After Turn
Broken canceling pawl on turn signal switch. Improperly
aligned canceling cam. Broken or loose canceling cam.
Turn Signals Inoperative (Both Sides)
Blown fuse. Faulty turn signal flasher. Loose bulkhead
connector. Loose or faulty rear wiring harness or terminals. Open
circuit to turn signal flasher. Open circuit in feed wire to turn
signal switch. Faulty switch connections. Open or grounded circuit in
wiring to external lights.
Turn Signal Inoperative (One Side)
Faulty external bulb. Poor ground at external light. Open
circuit in wiring to external light(s). Faulty turn signal/hazard
switch.
COMPONENT TESTS
CAUTION: When battery is disconnected, vehicle computer and memory
systems may lose memory data. Driveability problems may exist
until computer systems have completed a relearn cycle. See
COMPUTER RELEARN PROCEDURES article in GENERAL INFORMATION
before disconnecting battery.
NOTE: For additional testing procedures, see appropriate CRUISE
CONTROL SYSTEMS and WIPER/WASHER SYSTEMS articles.
NOTE: For component locations, see COMPONENT LOCATIONS.
HORN RELAY
1) Remove horn relay from Power Distribution Center (PDC).
Use label on PDC cover to identify and locate relay. Check continuity
between relay terminals No. 87A and 30. See Fig. 1. If continuity does
not exist, replace relay. If continuity exists, go to next step.
2) Check continuity between relay terminals No. 30 and 87. If
continuity exists, replace relay. If continuity does not exist, check
resistance between relay terminals No. 85 and 86. If resistance is not
70-80 ohms, replace relay. If resistance is 70-80 ohms, go to next
step.
3) Using jumper wires, connect positive battery voltage to

switch connector. See Fig. 4. If continuity does not exist, repair
open Black/Red wire. If continuity exists, go to next step.
3) Check continuity between ground and Black/Red wire at
steering column horn switch connector. If continuity does not exist,
go to next step. If continuity exists, repair short to ground in
Black/Red wire.
4) Continuity between horn switch terminal and ground.
Continuity should exist with horn switch depressed. Continuity should
not exist without horn switch depressed. If continuity is not as
specified, replace horn switch. If continuity is as specified, install
horn relay and go to HORN under COMPONENT TESTS.
TURN SIGNAL & HAZARD WARNING SYSTEMS
1) If bulbs burn out rapidly, check charging system for
overcharging condition. See appropriate GENERATORS & REGULATORS
article in STARTING & CHARGING SYSTEMS. If charging system is okay, go
to next step. If charging system is not okay, repair as necessary.
2) If problem is turn signals failing to cancel after a turn,
inspect multifunction switch or cancelling cam lobes on clockspring
for damage or improper installation. If problem exists, repair as
necessary. If problem does not exist, go to next step.
3) Turn ignition on. Actuate turn signal switch or hazard
warning switch. Observe turn signal indicator light(s) in instrument
cluster. If flash rate is very high, check for a bulb that is not lit
or is dimly lit. Repair circuit or replace bulb as necessary. If turn
signals fail to light, go to next step.
4) Turn ignition off. Check turn signal fuse in junction
block and/or hazard warning fuse in PDC. If fuses are okay, go to next
step. If either fuse is blown, repair short circuit and replace fuse.
5) Check for battery voltage at hazard warning fuse in PDC.
Turn ignition on. Check for battery voltage at turn signal fuse in
junction block. If battery voltage exists, go to next step. If battery
voltage does not exist, repair open circuit to battery or ignition
switch as necessary.
6) Turn ignition off. Disconnect negative battery cable.
Remove combination flasher from junction block and replace with a
known good unit. Connect battery cable and test operation of turn
signal and hazard warning systems. If operation is okay, discard
faulty flasher. If operation is not okay, go to next step.
7) Turn ignition on. Check for battery voltage at combination
flasher terminals No. 51 and 48 in junction block. If battery voltage
exists, go to next step. If battery voltage does not exist, repair
open circuit to fuse in junction block or PDC as necessary.
8) Disconnect negative battery cable. Check continuity
between combination flasher terminal No. 50 and ground. If continuity
exists, go to next step. If continuity does not exist, repair open
ground circuit.
9) Disconnect multifunction switch harness connector. Check
continuity between junction block terminal No. 4 and multifunction
switch terminal No. 13 (Pink wire). If continuity exists, go to next
step. If continuity does not exist, repair open in Pink wire between
multifunction switch and junction block.
10) Check continuity between junction block terminal No. 13
and multifunction switch terminal No. 17 (Red/White wire). If
continuity exists, test multifunction switch. See MULTIFUNCTION SWITCH
under COMPONENT TESTS. If continuity does not exist, repair open in
Red/White wire between junction block and multifunction switch.
REMOVAL & INSTALLATION
WARNING: Deactivate air bag system before performing any service

Horn Circuit
INSTRUMENT CLUSTER

Instrument Cluster Circuit (1 of 2)

Instrument Cluster Circuit (2 of 2)

Fig. 6: Locating Intake Manifold Air Heater Relays
Courtesy of Chrysler Corp.
Malfunction Indicator Light (MIL)
The MIL is located on the instrument panel, just below
tachometer and may also be referred to as the CHECK ENGINE light. MIL
comes on for a short period and then goes off as a bulb and wiring
circuit test each time ignition switch is turned to the ON position.
If Engine Control Module (ECM) receives an incorrect signal or
receives no signal from certain sensors or components, ECM will turn
on the MIL to warn the driver that a malfunction exists in the
electronic system.
Oil Pressure Gauge/Warning Light
Oil pressure gauge/warning light output from Engine Control
Module (ECM) to instrument cluster is routed on CCD Bus circuit.

VEH IC LE C O M MUNIC ATIO N

1999 D odge P ic ku p R 1500
1999 ACCESSORIES & EQUIPMENT
CHRY - Vehicle Communications
Ram Pickup
IDENTIFYING VEHICLE COMMUNICATION PROBLEMS
Connect scan tool to Data Link Connector (DLC) to retrieve
messages. If scan tool message is blank, disconnect scan tool. Ensure
ground circuit has continuity at DLC terminal No. 4. Ensure 12 volts
exists at DLC terminal No. 16. Check power to DLC terminal No. 16 from
Power Distribution Center (PDC) fuse No. 12. Try another scan tool
and/or cable. If scan tool DTC or fault message is present, see
following bus fault messages list and proceed to appropriate DTC or
fault message:
* BUS (+) & BUS (-) OPEN
* BUS (+) OPEN
* BUS (-) OPEN
* BUS (+) & BUS (-) SHORTED TOGETHER
* BUS BIAS LEVEL TOO HIGH
* BUS BIAS LEVEL TOO LOW
* NO BUS BIAS
* NO RESPONSE AIR BAG CONTROL MODULE
* NO RESPONSE CENTRAL TIMER MODULE
* NO RESPONSE INSTRUMENT CLUSTER
* NO RESPONSE POWERTRAIN CONTROL MODULE
* NO RESPONSE COMPASS/MINI-TRIP SYSTEM
* NO RESPONSE RADIO
* NO TERMINATION
* NOT RECEIVING BUS MESSAGES CORRECTLY
* BUS SHORT TO 5 VOLTS
* BUS SHORT TO BATTERY
* BUS SHORT TO GROUND
BUS (+) & BUS (-) OPEN, (BUS (+) OPEN OR BUS (-) OPEN)
NOTE: For connector terminal identification and wiring diagrams,
see BODY CONTROL COMPUTER - INTRODUCTION article. Perform
VERIFICATION TEST VER-1 after each repair.
CAUTION: Always turn ignition off prior to disconnecting any module
connector.
1) Disconnect scan tool. Ensure ignition is on. Using an
external voltmeter, measure voltage between ground and DLC terminal
No. 3 (Violet/Brown wire). If voltage is not 1.8-2.3 volts, go to step\
3). If voltage is 1.8-2.3 volts, go to next step.
2) Measure voltage between ground and DLC terminal No. 11
(White/Black wire). If voltage is not 1.8-2.3 volts, go to next step.
If voltage is 1.8-2.3 volts, replace scan tool cable or scan tool.
3) Connect jumper wire between ground and DLC connector
terminal No. 11 (White/Black wire). Turn ignition off. Remove
instrument cluster. Using external ohmmeter, measure resistance
between ground and instrument cluster connector C1 terminal No. 9
(White/Black wire). If resistance is less than 5 ohms, go to next
step. If resistance is 5 ohms or more, repair open White/Black wire.
4) Disconnect jumper wire. Connect jumper wire between ground
and DLC connector terminal No. 3 (White/Black wire). Measure