54-18
CHASSIS ELECTRICAL
-
Meters and Gauges
OPERATION
<Fuel gauge>
l
When the ignition key is at the “ON” position,
the fuel gauge is activated.
l
When there is much fuel, the unit’s resistance
is small and the current flowing in the circuit
is great, so the gauge’s indicator indicates in
the “F” area.
l When there is little fuel, the unit’s resistance
is high and the current flowing in the circuit
is small, so the gauge’s indicator indicates in
the
“E”
area.
<Engine
coolant temperature gauge>
l
When the ignition key is at the “ON” position,
the engine coolant temperature gauge is acti-
vated.
l
When the engine coolant temperature is high,
the unit’s resistance is low and there is a great
flow of current in the circuit, so the gauge’s
indicator indicates in the “H” area.
l
When the engine coolant temperature is low,
the unit’s resistance is high and there is a small
flow of current in the circuit, so the gauge’s
indicator indicates in the “C” area.
<Reed
switch (mechanical speedometer type)
/Speed sensor (electrical speedometer type)>
l Pulses are produced in accordance with the
vehicle speed, and vehicle-speed signals are
input to systems (the MFI system, etc.) that
regulate according to the vehicle speed.
TROUBLESHOOTING HINTS
1.
The fuel gauge doesn’t function, or shows the
incorrect indication.
(1) Disconnect the connector of the fuel pump
and gauge unit assembly; the ‘F” side is
indicated when terminal (5) is then
grounded.
l Check the fuel gauge.
2.
The engine coolant temperature gauge doesn’t
function, or shows the incorrect indication.
(1)
The
“l-l”
side is indicated when the connector
of the engine coolant temperature gauge
unit is disconnected and then grounded.
l
Check the engine coolant temperature
gauge unit.
3. Systems dependent upon control according to
the vehicle speed do not function correctly.
l Check the reed switch (mechanical
speedometer type)
l Check the speed sensor (electrical
speedometer type)
coil pressure gauge>
l
When the ignition key is at the “ON” position,
the oil pressure gauge is activated.
l
When oil pressure is high, the internal contacts
of the gauge unit are kept closed for a longer
period of time. This causes more current to
flow in the circuit, and the gauge pointer swings
to the high pressure side.
l
When oil pressure is low, the internal contacts
of the gauge unit open in a shorter period of
time. Therefore, there is less current flowing
in the circuit and the gauge pointer swings to
the low pressure side.
<Pressure gauge (TURBO)>
l
When the ignition key is set to the “ON” position,
the gauge indicator will be at
“0”.
l
When the engine is started, the indicator will
move from
“0”
to the minus (-) side, and then,
as the boost level increases, it will move to
the plus
(+)
side.
<Voltage gauge (NON-TURBO)>
l When the ignition key is placed in the “ON”
position, the voltage gauge operates and indi-
cates a battery voltage of approximately 12 V.
l
When the engine is started, the voltage gauge
indicates a battery voltage of 12 to 16 V, indicat-
ing that the battery is on charge.
4. The oil pressure gauge doesn’t function, or
shows the incorrect indication.
(1)
The “H” side is indicated when the connector
of the oil pressure gauge unit is discon-
nected and then grounded.
l Check the oil pressure gauge unit.
5.
The meter illumination light does not illuminate.
(1) The tail lights illuminate.
l Check the rheostat.
6. The voltage gauge doesn’t function, or shows
the incorrect indication.
l Check the voltage gauge.
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