12. Electrical System
198
Inspection
12.7.2 Cooling water temperature alarm
A water temperature lamp and a water temperature switch (thermo switch), backed up by an alarm in the
instrument panel, are used to monitor the temperature of the engine cooling water. A high thermal
expansion material is set on the end of the water temperature unit. When the cooling water temperature
reaches a specified high temperature, the contacts are closed, and an alarm lamp and buzzer are
activated at the instrument panel.
Problem
Inspection Item
Inspection method
Corrective action
Lamp not
illuminated when
main switch set
to ON.
1. Oil pressure lamp
blown out.
(1) Visual inspection.
(2) Lamp not illuminated even
when main switch set to ON
position and terminals of oil
pressure switch grounded.
Replace lamp.
2. Operation of oil
pressure switch.
Lamp illuminated when checked as
described in (2) above.
Replace oil pressure
switch.
Lamp not
extinguished
while engine
running.
1. Oil level low.
Stop engine and check oil level with
dipstick.
Add oil.
2. Oil pressure low.
Measure oil pressure.
Repair bearing wear
and adjust regulator
valve.
3. Oil pressure
faulty.
Switch faulty if abnormal at (1) and
(2) above.
Replace oil pressure
switch.
4. Wiring between
lamp and oil
pressure switch
faulty.
Cut the wiring between the lamp
and switch and wire with separate
wire.
Repair wiring harness.
Operating
temperature
ON
93-97 deg. C
Electric capacity
DC 12V, 1A
Response time
within 60 sec.
I.D. color
Black
Tightening torque
23.54-31.38 N•m
(2.40-3.20 kgf-m)
Water temperature
switch
Fresh water pump
Fuse
(Water temperature alarm circuit)
Battery
Main switch
Alarm buzzer
Pilot lamp
Water temperature unit
54.3 mm
M16 x 1.5
Black