TP-6073 4/06
52
Section 8 Component Troubleshooting
To further check generator set components, disconnect
the battery and remove the wiring harness plugs from
the controller circuit board. Use an ohmmeter to check
continuity and to isolate inoperative components as
described in Figure 8-2. Also refer to the corresponding
wiring diagram in Section 10.
Note:
Before performing ohmmeter checks, disconnect
the generator set battery to prevent damage to
the ohmmeter.
Component
Ohmmeter
Connections
Remarks
Results
Controller switch
P2-6 and P2-4
Ohmmeter on R x 1
scale. Place the rocker
switch in the START
position.
If functional, zero ohms (continuity). Any
resistance other than zero or very low ohms,
replace the switch.
Controller switch
P2-6 and P2-5
Ohmmeter on R x 1
scale. Place the rocker
switch in the STOP
position.
If functional, zero ohms (continuity). Any
resistance other than zero or very low ohms,
replace the switch.
K20 relay coil
P1-4 and P1-9
If functional, 85 ohms. Low resistance, shorted
K20 relay coil and/or wiring. High resistance, open
K20 relay and/or wiring.
K25 relay coil
P1-8 and P1-9
Oh
t
R
1
If functional, 85 ohms. Low resistance, shorted
K25 relay coil and/or wiring. High resistance, open
K25 relay and/or wiring.
Starter solenoid
(‘S’ relay)
P4-22 and battery (--)
cable.
NOTE:
Disconnect J4
and P4 to perform this
test.
Ohmmeter on R x 1
scale.
If functional, approx. 0.20--0.35 ohms at 27
_
C
(80
_
F).
Controller 15-amp
fuse and wiring
Battery positive (+)
cable and P1-14
NOTE:
Connect J4 and
P4 to perform this test.
If functional, zero or very low ohms. No reading
(infinity), open circuit or fuse blown.
Air heater relay
(AHR)
P4-8 and P4-1
If functional, approx. 16--20 ohms at 27
_
C (80
_
F).
P1 ground
connection
P1-9 and ground.
Ohmmeter on R x 1
scale.
If functional, zero ohms (continuity). Any other
reading indicates a poor ground connection.
Low oil pressure
(LOP) safety
shutdown switch
P1-15 and engine block
(ground).
NOTE:
J4 and P4 must
be connected to
perform this test.
Ohmmeter on R x 1
scale. This test is not
conclusive until the
temperature shutdown
switches are checked.
If functional, zero ohms (continuity). Then,
disconnect the LOP switch lead and isolate the
terminal. The meter reading should show an open
circuit.
High engine
temperature (HET)
safety shutdown
switch
P1-15 and engine block
(ground).
NOTE:
LOP switch lead
should be removed and
isolated.
NOTE:
J4 and P4 must
be connected to
perform this test.
Ohmmeter on R x 1
scale.
If functional, open circuit. Any continuity suggests
that temperature switch(es) are inoperative.
Disconnect individual leads to determine which
switch is inoperative.
Figure 8-2
Engine/Generator Set Component Testing with Ohmmeter
Summary of Contents for 10EOR
Page 10: ...10 Safety Precautions and Instructions TP 6073 4 06 Notes...
Page 12: ...TP 6073 4 06 12 Service Assistance Notes...
Page 22: ...TP 6073 4 06 22 Section 3 Intake and Exhaust System Notes...
Page 26: ...TP 6073 4 06 26 Section 4 Fuel System Notes...
Page 30: ...TP 6073 4 06 30 Section 5 Cooling System Notes...
Page 38: ...TP 6073 4 06 38 Section 6 Controller Troubleshooting Notes...
Page 54: ...TP 6073 4 06 54 Section 8 Component Troubleshooting Notes...
Page 60: ...TP 6073 4 06 60 Section 9 Generator Disassembly Reassembly Notes...
Page 82: ...TP 6073 4 06 82...
Page 83: ...TP 6073 4 06 83...
