COOLING SYSTEM TROUBLESHOOTING (cont)

TM 10-3930-638-24&P

2-12. COOLING SYSTEM TROUBLESHOOTING (cont)

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

3. COOLING SYSTEM NOT PRESSURIZED (cont)

Step 2. (cont)

a. If pressure drops quickly, radiator has serious leakage. Replace radiator (para 2-17c).

b. If pressure holds steady for two or more minutes, radiator check is satisfactory

c. If pressure drops slowly, radiator has seepage or slight leakage. Replace radiator (para 2-17c).

GAGES

TROUBLESHOOTING

MALFUNCTION

TEST OR INSPECTION

CORRECTIVE ACTION

1. ENGINE OIL PRESSURE GAGE DOES NOT INDICATE CORRECT PRESSURE

Place IGNITION switch in ON position.

Step 1.

Oil pressure gage should indicate zero.

a. If zero indication not obtained, proceed to step 2.

b. If zero indication obtained, proceed to step 3.

Step 2. Disconnect wire from oil pressure sender.

Oil pressure gage should indicate zero.

a. If oil pressure gage indicates 80 (full scale), repair or replace short circuited wire between oil

pressure sender and oil pressure gage.

b. If oil pressure gage indicates zero, replace oil pressure sender.

c. If oil pressure gage indicates other than zero or 80 (full scale), replace oil pressure gage.

Temporarily connect jumper wire between oil pressure gage SENDER terminal and chassis ground.

Step 3.

Place IGNITION switch in ON position.

Oil pressure gage should indicate 80 (full scale).

a. If 80 (full scale) indication not obtained, proceed to step 4.

b. If 80 (full scale) indication obtained, disconnect wire and proceed to step 5.

Step 4. Check for +24 Vdc between oil pressure gage IGN terminal and ground (IGNITION switch in ON

position).

a. If +24 Vdc not obtained, troubleshoot electrical system (para 2-19).

b. If +24 Vdc obtained, disconnect jumper wire between oil pressure gage SENDER terminal and

ground, and replace oil pressure gage (para 2-18b).