TM-9-2320-361-20
2-1/2-TON, 6x6, M44A2 SERIES TRUCKS (MULTIFUEL)
TECHNICAL MANUAL; UNIT MAINTENANCE
OCTOBER 1991
TM-9-2320-361-20 - Page 211 of 1207
TM 9-2320-361-20
Table 2-4. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
32. OIL PRESSURE GAGE INOPERATIVE
NOTE
If STE/ICE is available, perform NG31 - gage test (chapter 2,
section VII).
Test 1. Test oil pressure gage operation.
Step 1. Disconnect lead 36 at oil pressure sending unit.
Step 2. Turn accessory/ignition switch to ON position.
Step 3. Oil pressure gage should show MINIMUM pressure.
Step 4. Touch contact end of lead 36 to frame ground. Oil pressure gage should show MAXIMUM
pressure.
a. If oil pressure gage operates properly, go to test 3.
b. If oil pressure gage does not operate properly, go to test 2.
Test 2. Test battery voltage to oil pressure gage, go to malfunction 29, test 2.
Test 3. Test oil pressure sending unit.
Step 1. Set multimeter to RX1 scale.
Step 2. Connect negative lead to frame ground on engine.
Step 3. Touch positive lead to contact of oil pressure sending unit. Resistance should measure less
than 1 ohm with engine off (no oil pressure).
Step 4. If resistance is 1 ohm or more, replace oil pressure sending unit (para. 4-23).
Step 5. If resistance is less than 1 ohm, continue with step 6.
Step 6. Remove oil pressure sending unit (para. 4-23).
Step 7. Install mechanical gage.
Step 8. Start engine and check oil pressure on gage.
a. If oil pressure is 10 psi or above at idle, replace oil pressure sending unit (para. 4-23).
b. If oil pressure is less than 10 psi at idle, notify your supervisor.
Test 4. Test continuity of lead 36.
Step 1. Disconnect lead 36 from oil pressure gage (warm engine).
Step 2. Set multimeter to RX1 scale.
Step 3. Touch positive lead of multimeter to one end of lead 36 and negative lead of multimeter to
other end of lead 36.
a. If continuity is not present, replace or repair lead 36 (para. 4-51).
b. If continuity is present, replace oil pressure gage (para. 4-12).
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