Thermo King SGCO 3000, Manual

Page: 82 / 144

Electrical Maintenance
82
Oil Level Sensor
If the engine oil level drops below the actuation
level, the low oil level sensor (OLS) switch will
close. This will cause the controller to stop the
engine. The oil level switch is located in the oil
pan on the front side of the engine near the oil
filter.
Figure 44: Oil Level Sensor
Switch Test
1. Turn the unit ON/OFF switch to the “OFF”
position.
2. Disconnect the switch wires from the main
wire harness.
3. Connect a continuity tester to the two sockets
in the low oil level switch wire connector.
4. Check the oil level with the dipstick. Make
sure that it is between the low mark and the
full mark. Add oil if necessary.
5. The switch should be open and there should
be no continuity between the switch wires.
(When the oil level is between the low mark
and the full mark on the dipstick).
Bench test the switch if there is continuity
between the OLS and CH wires and there are no
short circuits in the wires.
Switch Removal and Installation
1. Disconnect the switch wires from the main
wire harness before removing the switch.
2. Remove the screw-in style switch by carefully
turning it out of the oil pan with a wrench.
3. To install the screw-in style switch, first
lubricate the O-ring on the switch with engine
oil. Then screw the switch into the oil pan.
4. Connect the switch wires to the main wire
harness after installing it.
Bench Test
1. Disconnect the switch wires from the main
wire harness. Remove the switch from the oil
pan.
2. Use a small container partially filled with
engine oil to check the float. Make sure that it
floats in engine oil and that it slides freely
between the upper and lower stops.
3. Slide the float up to the upper stop. Check the
continuity through the switch (between OLS
and CH wires). The switch should be open.
4. Slide the float down to the lower stop. Check
the continuity through the switch. The switch
should be closed.
5. Replace the switch if the float sinks or does
not slide freely, or if the switch does not open
and close properly.
AJA2064