TM 9-2320-260-20
Table 2-4. Electrical Troubleshooting (Contd).
MALFUNCTION
TEST OR INSPECTION
CORRECTIVE ACTION
3. STARTER MOTOR OPERATES, BUT ENGINE CRANKS SLOWLY
NOTE
If STE/ICE is available, perform NG80 starter circuit tests
Test 1. Check batteries for overheating.
Step 1. Crank engine for 15 seconds.
Step 2. Check batteries for overheating by feeling battery terminal connections. If battery
terminals are hot:
a. Clean corroded connections to bright metal.
b. Tighten all loose connections at batteries, ground, and starter.
Test 2. Test specific gravity for each battery.
Perform a specific gravity test (TM 9-6140-200-14). Batteries must test 1.225 or greater.
Temperature must be corrected, and each cell in a battery must test within 0.025 points of
the others.
a. Charge all batteries not meeting requirements (TM 9-6140-200-14) and check specific
gravity again.
b. If 0.025 point variation still exists within any battery, replace battery (para. 4-49).
Test 3. Test starter motor voltage.
Step 1. Set multimeter to a range that will measure 24 volts.
Step 2. Position battery switch to ON position.
Step 3. Touch positive lead of multimeter to contact end of lead 6 at starter motor.
Step 4. Touch negative lead of multimeter to contact end of ground strap at end plate on starter.
Step 5. Crank engine and observe cranking voltage.
a. If voltage is 19 volts or greater, go to test 4.
b. If voltage is less than 19 volts, go to malfunction 1, tests 1 and 2.
Test 4. Test starter motor-to-solenoid strap voltage drop.
Step 1. Set multimeter to a range that will measure tenths of a volt.
Step 2. Touch positive lead of multimeter to contact end of ground strap at solenoid.
Step 3. Touch negative lead of multimeter to contact end of ground strap at starter motor.
Step 4. Crank engine and observe multimeter.
a. Voltage reading exceeding 0.2 volts indicates a bad connection at starter. Clean and
tighten all connections and retest.
b. Replace starter if retest fails (para. 4-5).
Test 5. Test starter motor solenoid contact voltage drop.
Step 1. Set multimeter to a range that will measure tenths of a volt.
Step 2. Touch positive lead of multimeter to contact end of lead 6 at solenoid.
Step 3. Touch negative lead of multimeter to contact end of ground strap at solenoid.
Step 4. Crank engine and observe multimeter.
a. Replace starter motor if voltage reading exceeds 0.4 volts (para. 4-5).
b. If malfunction still exists, go to test 6.
2-110
