TM 1-1740-221-13&P&P
FIELD MAINTENANCE
PARK POSITION BRAKE LIMIT SWITCHES
INITIAL SETUP:
Test Equipment
References
Multimeter (WP 0157, Item 14)
Tools and Special Tools
General Mechanic Tool Box (WP 0157, Item 24)
Equipment Condition
Personnel Required
Engine Shut Down
91B, Light Wheel Vehicle Mechanic
INSPECTION
Inspect upper and lower switch assemblies for mount security, corrosion, loose wiring or broken terminals or any
damage affecting serviceability.
END OF TASK
TEST
NOTE
Disconnect battery negative cables prior to limit switch tests.
Upper Limit Switch
1. Remove upper limit switch this work package.
2. Ohms test at (Figure 2, Item 2) for continuity or from the normally closed to the common terminal.
3. Actuate switch (push button on bottom of switch) to open the contacts.
4. Ohms test at (Figure 2, Item 2) for open condition (no continuity).
5. Replace upper limit switch if ohms test fails.
Lower Limit Switch
1. Remove lower limit switch this work package.
2. Remove lower limit switch cover this work package.
3. Ohms test across limit switch pins (Figure 3, Item 5) for continuity.
4. Rotate actuator arm (Figure 3, Item 6) counter clockwise until switch clicks or opens.
5. Ohms test across limit switch pins (Figure 3, Item 5) for open condition (no continuity).
6. Replace lower limit switch if ohms test fails.
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