Kohler 7.5EOR Service page 52

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.
Component
P2-6 and P2-4
Controller switch Controller switch
P2-6 and P2-5
K20 relay coil P1-4 and P1-9
K25 relay coil P1-8 and P1-9
P4-22 and battery (--)
cable.
Starter solenoid
NOTE: Disconnect J4
('S' relay)
and P4 to perform this
test.
Battery positive (+)
Controller 15-amp cable and P1-14
fuse and wiring NOTE: Connect J4 and
P4 to perform this test.
Air heater relay
P4-8 and P4-1
(AHR)
P1 ground
P1-9 and ground.
connection
P1-15 and engine block
Low oil pressure (ground).
(LOP) safety NOTE: J4 and P4 must
shutdown switch be connected to
perform this test.
P1-15 and engine block
(ground).
High engine NOTE: LOP switch lead
temperature (HET) should be removed and
isolated.
safety shutdown
NOTE: J4 and P4 must
switch
be connected to
perform this test.
Figure 8-2 Engine/Generator Set Component Testing with Ohmmeter
52 Section 8 Component Troubleshooting
Ohmmeter
Connections
Ohmmeter on R x 1
scale. Place the rocker
switch in the START
position.
Ohmmeter on R x 1
scale. Place the rocker
switch in the STOP
position.
Oh Ohmmeter on R x 1
scale.
Ohmmeter on R x 1
scale.
Ohmmeter on R x 1
scale. This test is not
conclusive until the
temperature shutdown
switches are checked.
Ohmmeter on R x 1
scale.
Note: Before performing ohmmeter checks, disconnect
the generator set battery to prevent damage to
the ohmmeter.
Remarks
If functional, zero ohms (continuity). Any
resistance other than zero or very low ohms,
replace the switch.
If functional, zero ohms (continuity). Any
resistance other than zero or very low ohms,
replace the switch.
If functional, 85 ohms. Low resistance, shorted
K20 relay coil and/or wiring. High resistance, open
K20 relay and/or wiring.
If functional, 85 ohms. Low resistance, shorted
K25 relay coil and/or wiring. High resistance, open
K25 relay and/or wiring.
t R 1
If functional, approx. 0.20--0.35 ohms at 27_C
(80_F).
If functional, zero or very low ohms. No reading
(infinity), open circuit or fuse blown.
If functional, approx. 16--20 ohms at 27_C (80_F).
If functional, zero ohms (continuity). Any other
reading indicates a poor ground connection.
If functional, zero ohms (continuity). Then,
disconnect the LOP switch lead and isolate the
terminal. The meter reading should show an open
circuit.
If functional, open circuit. Any continuity suggests
that temperature switch(es) are inoperative.
Disconnect individual leads to determine which
switch is inoperative.
Results
TP-6073 4/06