TM 9-2320-361-20 Table 2-4. Electrical Troubleshooting (Contd). MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 34. IN-TANK FUEL PUMP INOPERATIVE Test 1. Check for fuel pump operation. Step 1. Turn accessory/ignition switch to ON position. Step 2. Listen or feel for fuel pump humming or vibration at top of pump. Step 3. If vibration can be felt or heard, go to test 4. Step 4. If no vibration can be felt or heard, go to test 2. Test 2. Test input voltage and ground to fuel pump. Step 1. Remove lead 654 from fuel pump. Step 2. Set multimeter to a voltage scale that will measure 24 Vdc. Step 3. Connect positive lead of multimeter to lead 654 and negative lead of multimeter to ground lead 79. a. If battery voltage is not present, go to test 5. b. If battery voltage is present, go to test 3. 2-129