Dodge RAM TRUCK 1500 1995 Service Manual page 642

B R
8W-40 INSTRUMENT CLUSTER
8W
- 4 0 - 1
INSTRUMENT CLUSTER
, . . INDEX
page
ABS Warning Lamp 2
Airbag Warning Lamp . . . . . . . . . . . . . . . . . . . . . . .
2
Diagram Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Engine Coolant Temperature Gauge . . . . . . . . . . . . 1
Four-Wheel Drive Indicator . .
3
Fuel Gauge 1
High-Beam Indicator Lamp
2
Instrument Cluster 1
Low Fuel Warning Lamp 1
Low Washer Fluid
2
Malfunction Indicator Lamp (MIL) .
2
INSTRUMENT CLUSTER
The instrument cluster contains the gauges and
warning lamps. All gauges have magnetic move­
ments.
When the ignition switch is in the START or RUN
position, circuit A21 feeds circuit F14 through a bus
bar in the fuse block and fuse 12. Circuit Al from
fuse 3 in the Power Distribution Center (PDC) sup­
plies voltage to circuit A21.
Circuit F14 provides battery voltage for the warn­
ing lamps (except seat belt indicator lamp), transmis­
sion up shift lamp, and all gauges.
Circuit E2 from fuse 13 in the fuse block feeds the
illumination lamps. Circuit El from the headlamp
switch powers fuse 13 when the parking lamps or
headlamp are ON.
Circuit Z3 provides ground for the indicator lamps
and illumination lamps. Circuit Zll provides the
ground path for the gauges.
ENGINE COOLANT TEMPERATURE GAUGE
Circuit G20 connects the engine coolant tempera­
ture gauge to the engine coolant temperature sensor.
The sensor is a variable resistor and case grounded
to the engine on all engines except the V-10. The
V-10 engine coolant temperature sensor has an exter­
nal ground. Circuit F14 connects to the instrument
cluster and supplies voltage for the gauge.
The gauge uses two coils. Current passing through
the coils creates a magnetic field. Position of the
gauge needle is controlled by the amount of current
passing through the coils to ground at the sensor.
FUEL GAUGE
Circuit G4 connects the fuel level sensor to the fuel
gauge in the instrument cluster. Circuit F14 from
fuse 12 in the fuse block supplies voltage to the fuel
page
Manual Transmission Up-Shift Lamp . 2
Oil Pressure Gauge 1
Oil Pressure Warning Lamp 1
Parking Brake Lamp
2
PTO Lamp . . 3
Seat Belt Indicator Warning Lamp . 2
Service Reminder Indicator (SRI) Lamp . . 3
Speedometer
2
Tachometer . . 2
Turn Signal Indicator Lamps 2
Voltmeter .
2
gauge. The fuel level sensor draws voltage from cir­
cuit F14 through the fuel gauge on circuit G4.
As current flows through the coils in the fuel
gauge, it creates a magnetic field. The magnetic field
controls the position of the fuel gauge pointer.
The fuel level sensor contains a variable resistor.
As the position of the float arm on the fuel level sen­
sor changes, the resistor changes the current flow
through the fuel gauge circuit. A change in current
flow alters the magnetic field in the fuel gauge,
which changes the pointer position.
Circuit Zll provides the ground path for the fuel
level sensor.
LOW FUEL WARNING LAMP
Circuit G4 connects the fuel level sensor to the low
fuel relay in the instrument cluster. When the fuel
level in the fuel tank reaches a calibrated level, the
low fuel warning lamp relay illuminates the lamp.
OIL PRESSURE GAUGE
The case grounded oil pressure sensor is a variable
resistor that connects to circuits G60 and G6. Circuit
G60 connects to the oil pressure gauge. Circuit G6
connects to the oil pressure warning lamp.
Circuit F14 connects to the instrument cluster and
supplies battery voltage to oil pressure gauge. The
gauge uses two coils. Current passing through the
coils creates a magnetic field. Position of the gauge
needle is controlled by the amount of current passing
through the coils to ground at the sensor.
OIL PRESSURE WARNING LAMP
The case grounded oil pressure sensor is a variable
resistor that connects to circuits G60 and G6. Circuit
G60 connects to the oil pressure gauge. Circuit G6
connects to the oil pressure warning lamp.