Circuit Operation - Gauges Cluster

Only those indicators and gages that are not described in connection with other circuits are explained in this circuit operation. See the circuit referred to for its complete operation.

Fuel Gage
The pointer of the fuel gage is moved by the magnetic fields of two coils. The coils are at right angles to each other. Battery voltage is applied to the E coil, and the circuit divides at the opposite end of this coil. Another goes to ground through the variable resistor of the fuel tank unit.

When the tank is low, the resistance of the fuel tank unit is low. A large flow of current passes through the E coil and the fuel tank unit resistor. This pulls the pointer towards E on the scale. When the tank is full, the fuel tank unit resistance is high. More current now flows through the F coil, moving the pointer to F on the scale.

With two coils operating the pointer, the fuel gage is not affected by changes in the voltage of the system.

Engine Coolant Temperature Gage
The engine coolant temperature gage is also operated by two coils. Battery voltage is applied to both coils. One is grounded directly and the other is grounded through the Engine Coolant Temperature Sensor. The engine coolant temperature sensor has 44 ohms resistance at 280° F (138° C) and its resistance increases at lower temperatures. Resistance is approximately 1365 ohms at 100° F (37° C). This causes the current through the engine coolant temperature sensor and one coil to increase as the coolant temperature increases and moves the pointer.

Voltmeter
The voltmeter measures the electrical system's voltage with ignition switch in "RUN". With the engine stopped, the voltmeter indicates Battery condition. With the engine running, the voltmeter indicates charging system operation.

Speedometer and Odometer
The vehicle speed sensor (VSS) generates a signal that indicates the speed of the solid state PCM to supply inputs to the cruise control module, speedometer and odometer.

The vehicle speed sensor is mounted in the transaxle. A magnet rotates near a coil, producing voltage pulses in the coil. The frequency of the AC voltage coming from this coil depends on the vehicle speed. The VSS sends pulses to the PCM at the rate of 40,000 pulses per mile.

Tailgate Ajar Indicator (Station Wagon)
With the ignition switch in "RUN", "BULB TEST", or "START", voltage is applied through the GAGES Fuse to the indicator. When the tailgate is ajar, the tailgate ajar switch closes, providing a ground for the indicator.