Gauge Senders; Oil Pressure Sender Testing; Water Temperature Sender Testing - Kohler 40COZ/33CFOZ Service Manual

7.13 Gauge Senders

The resistance of the oil pressure and water
temperature sender output signals varies as the
respective pressure and temperature change. Use the
resistance change for verification of sender function.
Disconnect all leads from the sender before checking
resistance. If the sender functions and the gauge does
not function, check the engine wiring harness, leads,
and connectors before replacing the gauge.
Note: Some generator sets may have senders/
switches incorporated with the engine ECM
(electronic control module). Identify engine ECM
senders/switches by lead designations listed in
the following testing information.
Section 9, Wiring Diagrams for additional lead
identification information. Use the engine service
manual for
senders/switches.

7.13.1 Oil Pressure Sender Testing

Disconnect the oil pressure sender lead 7C.
Figure 7-21. Check the sender resistance with an
ohmmeter. Compare the resistance values when the
generator set is shut down and when it is running at
operating temperature to the values shown in
Section 1.2, Specifications.
Use a mechanical oil pressure gauge to further verify
correct readings.
Lead 7C
Figure 7-21 Oil Pressure Sender, Typical
76 Section 7 Component Testing and Adjustment
Refer to
troubleshooting ECM
See
TP-5353-7
7.13.2 Water Temperature Sender
Testing
The water temperature sender is a single function,
single-terminal type. See Figure 7-22.
Lead 5
Figure 7-22 Water Temperature Sender, Typical
Disconnect the water temperature sender lead 5. Check
the sender resistances with an ohmmeter. Compare the
resistance values when the generator set is shut down
and when it is running at operating temperature to the
values in Section 1.2, Specifications.
TP-5353-7
TP-5737 5/01