TM 9-2320-361-20 Table 2-4. Electrical Troubleshooting (Contd). MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 3. STARTER MOTOR OPERATES, BUT ENGINE CRANKS SLOWLY NOTE Test 1. Test 2. If STE/ICE is available, perform NG80 - starter circuit tests (chapter 2, section VII). Check batteries for overheating by cranking engine for 15 seconds and feeling battery terminal connections. If battery terminal is hot, a loose or corroded connection is indicated. a. Clean corroded connection to bright metal. b. Tighten all loose connections at batteries, ground, and starter. Test specific gravity for each battery. Perform a specific gravity test (TM 9-6140-200-14), Batteries must test 1.255 or greater, temperature 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, it is defective and must be replaced (para. 4-49). Test starter motor voltage. Test 3. Step 1. Set multimeter to a voltage range that will measure 24 Vdc. Step 2. Connect multimeter positive lead to positive terminal lug 6 of starter motor and negative lead to terminal lug 5 on end plate of starter motor. Step 3. Crank engine (TM 9-2320-361-10) and observe cranking voltage on multimeter. Voltage should exceed 19 Vdc. If voltage is less than 19 Vdc, clean and tighten starter motor connections. Test 4. Test starter motor-to-solenoid strap voltage drop. Step 1. Set multimeter to a voltage range that will measure tenths of a volt. Step 2. Connect multimeter negative lead to positive terminal lug 6 of starter motor and multimeter positive lead to starter motor solenoid terminal lug 3. Step 3. Crank engine (TM 9-2320-361-10) and observe multimeter. A voltage reading exceeding 0.2 volts indicates a bad connection at starter motor terminal lug 3 and terminal lug 6 of solenoid. Clean and tighten connections. Test 5. Test starter motor solenoid contact voltage drop. Step 1. Set multimeter to a voltage range that will measure tenths of a volt. Step 2. Connect multimeter between starter motor solenoid terminal lugs 3 and 2. Step 3. Crank engine (TM 9-2320-361-10) and observe multimeter. A voltage reading exceeding 0.4 volts indicates a defective starter motor solenoid. a. Replace starter motor and solenoid assembly (para. 4-7). b. If malfunction still exists, go to tests 6, 7, and 8. Test 6. Test negative cable 7 voltage drop from batteries to starter motor. Step 1. Step 2. Step 3. Set multimeter to voltage range that will measure tenths of a volt. Connect multimeter positive lead to terminal stud on end plate of starter motor and negative lead to frame ground. Crank engine (TM 9-2320-361-10) and observe multimeter. A voltage reading exceeding 0.4 volts indicates a defective starter motor solenoid. a. Replace starter motor and solenoid assembly (para. 4-7). b. If malfunction still exists, go to tests 7 and 8. 2-86