Warning Devices - Yanmar 4JH2E Service Manual

Chapter 9 Electrical System
6. Warning Devices
~~~,;_~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~4JH
Series
6. Warning Devices
6·1 Oil pressure alarm
If the engine oil pressure is below
0.1~0.3
kg/cm' (1.42
~
4.26 lb/in.'), with the main switch in the ON position, the
contacts of the oil pressure switch are closed by a
spring. and the lamp is illuminated through the lamp - oil
pressure switch ---- ground circuit system. If the oil pressure
is normal, the switch contacts are opened by the
lubricating oil pressure and the lamp remains off.
Main switch
-=-Battery
(Oil pressure alarm circuit)
Oil
pressure
Oil pressure switch
Inspection
Problem
Lamp not illuminated when
main switch set to ON
Lamp not extinguished
while engine running
Printed in Japan
AOA/029-9002
Oil pressure
-
Inspection Item
1. Oil
pressure tamp
blown out
2. Operation of oil pressure
switch
1. Oil level low
2. OH pressure low
3. Oil pressure faulty
4. Wiring between lamp and oil
pressure switch faulty
Lube oil
A
pressure-y
switch
Cylinder· body main gallery
Part No.
Rated
voltage
Operation pressure
Lamp capacity
Inspection method
(1) Visual inspection
(2) Lamp not illuminated even
when main switch set to ON
position and terminals of oil
pressure switch grounded
Lamp illuminated when checked
as described in (2) above
Stop engine and check oil
level with dipstick
Measure oil pressure
Switch faulty if abnormal at (1)
and (2) above
Cut the wiring between the
lamp and switch and wire with
separate wire
9-39
124060-39451
12V
0.1 "'0.3kg/cmJ
(1.422
~
4.2661b/in.')
5W
Corrective action
Replace lamp
Replace oil pressure switch
Add
oil
Repair bearing wear and
adjust regulator valve
Replace oil pressure switch
Repair wiring harness