ARMY TM 9-6115-464-12
AIR FORCE TO 35C2-3-445-1
NAVY NAVFAC P-8-624-12
Suspend over-temperature switch in a container of clean oil so that sensing element is completely
immersed but not touching the sides or bottom of the container.
Suspend a reliable thermometer in the container. Do not allow the end of the thermometer to reset
on the bottom of the container.
Using an ohmmeter, check continuity between pins A and D (figures FO-1 and FO-2) and between
pins B and C of the switch connector. A and D should indicate continuity and B and C should indicate
Attach the ohmmeter leads to pins A and D.
Do not exceed 250°F (121.1°C) as oil may ignite.
Gradually heat the oil, stirring so that heat will be evenly distributed, and observe the thermometer and
At 220°F ± 3°F (104.8 ± 1.5°C) the ohmmeter should indicate discontinuity.
Check continuity between pins B and C. Ohmmeter should indicate continuity.
Replace the over-temperature switch if it fails to operate within the above limits.
(1) Install over-temperature switch into cylinder block and tighten to 12 to 15 lbs-ft torque.
(2) Refer to paragraph 3-27 and service radiator.
OIL PRESSURE TRANSMITTER (Figure 1-5).
Test oil pressure transmitter in accordance with paragraph c. below prior to removal.
(1) Remove nut, washer, and electrical lead from oil pressure transmitter.
(2) Unscrew oil pressure transmitter from coupling in engine block.
b. Cleaning and Inspection.
(1) Clean oil pressure transmitter with dry, filtered compressed air and a soft bristle brush or wipe with
a dean, lint-free cloth lightly moistened with an approved solvent.
(2) Inspect oil pressure transmitter for cracked casing, stripped or damaged threads, corrosion, or other visible
Disconnect electrical lead to oil pressure transmitter.
Connect an ohmmeter between transmitter terminal and casing. Readings should indicate 15 ohms at
30 psi and 300 ohms at 60 psi.
Refer to paragraph 2-6 and start the engine.
Allow the engine to operate until normal operating temperature is indicated on the temperature gauge.
Observe ohmmeter. Resistance shall be as specified in paragraph 1-11.