OIL PRESSURE SWITCHES
91B, Light Wheel Vehicle Mechanic
Tools and Special Tools
Engine Shut Down and Cool
Inspect oil pressure switches for mounting security (no leaks) wiring for security, corrosion and
any damage affecting serviceability.
Pressure Switch Continuity Tests
Eye protection required when applying air pressure to switches.
Oil Pressure Switch (Warning Light) Remove switch (Figure 1, Item 1) and ohms check for continuity
(normally closed) from the terminal connection to the switch case threads. Apply air pressure to the switch and
ohms check for loss of continuity (switch open). If switch fails either test, replace defective switch.
Oil Pressure Switch (Hour Meter) Remove switch (Figure 2, Item 1) and ohms check (no continuity, normally
open) across the two electrical terminals. Apply air pressure and ohms check for continuity (pressure closes).
If switch fails either test, replace defective switch.
END OF TASK
OIL PRESSURE SWITCH (WARNING LIGHT)
Label or tag all wiring terminals after removal to aid with switch reinstallation.
Remove mount screw (Figure 1, Item 3).
Remove wire 30 (Figure 1, Item 2).