Gauges Cluster
BASE AND GAGES INSTRUMENT CLUSTERSThe operation of the Gages Instrument Cluster is the same as the Base Cluster with the addition of an Oil Pressure Gage, a Coolant Temperature Gage, a Voltmeter and a "CHECK GAGES" Warning Indicator.
CLUSTER ILLUMINATION
The Cluster Illumination Lamps are supplied voltage by the Panel and Interior Lamps Control Switch through the INST LPS Fuse and the GRA (8) wire. Ground for the lamps is provided through the BLK (150) wire,
SPEEDOMETER
The Speedometer receives an A/C output signal from the Vehicle Speed Sensor Buffer (DRAC) through the LT BLU/BLK (824) wire and converts this to an analog (needle-type) display of vehicle speed.
FUEL GAGE
Voltage to the Fuel Gage is supplied through the PNK/BLK (39) wire with the Ignition Switch in START or RUN. The movement of the Fuel Gage needle is controlled by current flowing through two coils in the gage. This movement creates magnetic fields in the coils. The amount of current flowing through each coil is controlled by the Fuel Tank Sender unit. Voltage from the PNK/BLK (9) wire is applied to one end of the EMPTY (E) coil. The other end of the E-coil is connected to the FULL (F) coil and BLK (150) wire and the Fuel Tank Sender and PNK (30) wire.
When the Fuel Tank is empty, the resistance of the Fuel Tank Sender is low (one ohm). This allows more current to flow through the E-coil and the Sender resistor, and the magnetic field in the E-coil pulls the pointer toward E on the Fuel Gage.
When the Fuel Tank is Full, the resistance of the Fuel Tank Sender is high (88 ohms). This allows more current to flow through the F-coil to ground through the BLK (150) wire, and the magnetic field in the F-coil pulls the pointer toward F on the Fuel Gage.
OIL PRESSURE GAGE
The Oil Pressure Gage operates the same as the Fuel Gage. The resistance controlling the current flow through the coils (High coil and Low coil is provided by the Oil Pressure Sender through the TAN (31) wire. With no oil pressure, the resistance of the sender is low (one ohm). At 275 kPa (40 psi), the resistance is high (44 ohms).
COOLANT TEMPERATURE GAGE
The Coolant Temperature Gage also operates the same as the Fuel Gage and Oil Pressure Gage. Resistance controlling the coils (Hot coil and Cold coil is provided by the Coolant Temperature Sender though the DK GRN (35) wire. However, with a coolant temperature of 40°C (104°F), resistance of the sender is high (1365 ohms). With a coolant temperature of 125°C (257°F), resistance of the sender is low (55 ohms).
VOLTMETER
The Voltmeter indicates battery voltage with the Ignition Switch in RUN and the engine not running. With the engine running, the voltmeter indicates generator output.
INDICATOR LAMPS
Voltage to the Brake, SERVICE ENGINE SOON, CHECK GAGES and SHIFT Indicators is provided through the IGN/GAUGES Fuse and the PNK/BLK (39) wire with the Ignition Switch in START or RUN. Ground for the Indicators is provided by various components in the vehicle.
Voltage to the RIGHT TURN, LEFT TURN, HIGH BEAM and SAFETY BELT Indicators is provided by various components in the vehicle. Ground is provided to these Indicators through the BLK (150) wire.
BRAKE INDICATOR
Ground to light the BRAKE Indicator is provided in one of four ways. When the Ignition Switch is turned to RUN, the Antilock Brake Module provides a ground to the indicator for about two seconds through the TAN/WHT (33) wire. This indicates the antilock brake system is operating properly. If a malfunction occurs in the RWAL system or the hydraulic portion of the four-wheel antilock brake system, the BRAKE Indicator will light.
The BRAKE Indicator will light when the parking brake is set. This closes the Parking Brake Switch providing a ground to the BRAKE Indicator.
If a brake hydraulic circuit loses pressure, the Brake Pressure Warning Switch closes, providing a ground to the BRAKE Indicator.
GENERATOR INDICATOR
Ground to the GEN (Generator) Indicator is controlled by the lamp driver circuit in the Generator. The GEN Indicator will light whenever undervoltage, overvoltage or a stopped Generator is detected by the lamp driver circuit.
SERVICE ENGINE SOON INDICATOR
The SERVICE ENGINE SOON Indicator will light if a problem is detected wfth the engine running and the vehicle moving. Refer to the ENGINE CONTROLS for Diagnosis.
CHECK GAGES INDICATOR
The CHECK GAGES Indicator lights to alert the driver to a low oil pressure or high coolant temperature condition. The signals from the Engine Coolant Sender and the Engine Oil Pressure Sender are monitored by the Check Gages Lamp Driver which is part of the Temperature Gage. The lamp driver controls the ground to the Check Gages Lamp mounted in the instrument cluster.
SHIFT INDICATOR
On vehicles with a manual transmission, the SHIFT Indicator lights when the vehicle should be shifted to the next higher gear for better fuel economy. The ECM uses engine data such as rpm, vehicle speed and intake manifold vacuum to compute an efficient shift point. The ECM provides a ground to light the Shift Indicator through the TAN/BLK (456) wire
TURN INDICATORS
Voltage to the Turn Indicators is provided by the Turn Switch or Hazard Switch. Voltage to the LH Indicator is supplied through the LT BLU (14) wire. The RH Indicator is supplied voltage through the DK BLU (15) wire. Refer to EXTERIOR LAMPS for Diagnosis.
HIGH BEAM INDICATOR
Voltage to the High Beam Indicator is provided by the LT GRN (11) wire with the Headlamps On and the Headlamp Dimmer Switch in HI position. Refer to EXTERIOR LAMPS for Diagnosis.
SAFETY BELT WARNING INDICATOR
Refer to INTERIOR LAMPS and AUDIBLE WARNINGS for further information.