Operation CHARM: Car repair manuals for everyone.

Without Tachometer

COOLANT TEMPERATURE GAUGE

The 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 thermo unit. As the resistance in the thermo unit 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. When voltage from fuse C7 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 sending unit. As the resistance in the sending unit varies, current through the gauge coils changes. The gauge needle moves according to the changing magnetic field. The fuel tank unit's resistance varies from approximately 3 ± 2 ohms with fuel tank full to 110 ± 7 ohms with the tank empty.

OIL PRESSURE GAUGE

The oil pressure 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 sending unit. As the resistance in the sending unit varies, current through the gauge coils changes. The gauge needle moves according to the changing magnetic field.

VOLTMETER

The voltmeter measures the voltage through fuse 7 when the starter switch is in ON or START.