Gauges
COOLANT TEMPERATURE GAUGEThe coolant temperature gauge consists of two intersecting coils wound around a permanent magnet rotor. When voltage from fuse 7 is applied to the coils, a magnetic field is generated. This causes the rotor to rotate and the gauge needle to move. The magnetic field is controlled by the sender. As the resistance in the sender varies, current through the gauge coils changes. The gauge needle moves according to the changing magnetic field.
FUEL GAUGE
The fuel gauge consists of two intersecting coils wound around a permanent magnet rotor (see coolant temperature gauge above for operation). The fuel gauge sender's resistance varies from approximately 3 + 2 ohms with fuel tank full to 110 ± 7 ohms with the tank empty.
TACHOMETER
The tachometer displays engine speed in RPM. Voltage pulses are taken from the ignition system and sent to the tachometer. The tachometer responds to the frequency of the voltage pulses, which increases with engine speed. Solid-state circuits process these pulses into a signal that causes the gauge needle to move.