Performance
With the Ignition Switch in RUN or START, voltage is applied to the Instrument Cluster through the CLUSTER Fuse, and power is supplied to the gauges and indicator under certain conditions.
Brake Indicator
The Brake Indicator comes on: 1) with the Ignition Switch in START to test the bulb (this connection is closed just before reaching the START position); 2) with the Brake Fluid Level Switch closed (low brake fluid level); 3) with the Anti-lock Pressure Switch closed (low pressure in system); and 4) with park brake applied.
Alternator Warning Indicator
The Alternator Warning Indicator, grounded through circuit 904, comes on if the voltage in the Voltage Regulator drops below the preset level.
Door Ajar Indicator
The Door Ajar Indicator comes on whenever a door is not completely closed.
Alarm Indicator
The Alarm Indicator comes on when the Ignition Switch is in the OFF position and a door is opened.
Check Engine Indicator
The Check Engine Indicator is turned on by the EEC Module when a fault is sensed in the EEC IV System.
Anti-lock Indicator
The Anti-lock Indicator is controlled by the Anti-lock Brake System.
Fasten Belts Indicator
The Fasten Belts Indicator is controlled by the Passive Restraint System.
Firm Ride Indicator
The Firm Ride Indicator comes on with the Ignition Switch in RUN and the suspension in he firm mode.
Shift Indicator
The Shift Indicator is controlled by the Electronic Engine Control (EEC), which grounds the Indicator when the engine has reached an efficient shift point.
Check Gauge Indicator
The Check Gauge Indicator indicates a critical indication on at least one of the gauges. This light will glow continuously with the key in the ON position if the engine coolant temperature is high (approximately above the last 10% of the normal band), the engine oil pressure is low (approximately below the first 15% of the normal bank), or the fuel is very low (below 1/16th).
Fuel Gauge
The Fuel Gauge is connected to the Fuel Gauge Sender through the Anti-slosh Module. The Sender is a variable resistor connected to a float in the fuel tank. When the fuel level is low, resistance is low; when fuel level is high , resistance is high.
The Anti-slosh Module provides a delay circuit to the Fuel Gauge to prevent the gauge from fluctuating as a result of fuel movement.
Temperature Gauge
The Temperature Gauge connects to the Engine Coolant Temperature Sender. The Sender is a temperature-sensitive variable resistor. When coolant temperature is low, resistance is high; when coolant temperature is high, resistance is low.
Oil Pressure Gauge
The Oil Pressure Gauge is connected to a 20 ohm resistor and an Oil Pressure Switch. When there is low oil pressure, the Switch is open, causing the Gauge to indicate low. When there is proper oil pressure, the Switch is closed and the 20 ohm resistor is connected to ground, causing the Gauge to indicate in the normal mid-scale oil pressure. This resistor is located on the printed circuit of the Performance Cluster.
Tachometer
The Tachometer receives a signal from the Ignition Coil when the engine is running. The Tachometer then displays this signal as revolutions per minute.
Speedometer Assembly
The Speedometer Assembly includes the Speedometer, the Odometer and the Trip Odometer. All three are electronically controlled by a solid-state device that uses an input signal from the Vehicle Speed Sensor (VSS).
The Speedometer Assembly (-17255-) is serviceable only as a unit.
Vacuum/Boost Gauge
The Vacuum/Boost Gauge is designed to indicate engine manifold pressure. A vacuum line is connected to the gauge in the cluster. This vacuum line is routed through the dash panel and attaches to a vacuum port on the intake assembly.