TM 9-2320-361-20 Table 2-4. Electrical Troubleshooting (Contd). MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 26. ALL STOPLIGHTS ARE INOPERATIVE Test 1. Check stoplight switch for input voltage. Step 1. Turn main light switch to SERVICE DRIVE position. Step 2. Set multimeter to a voltage range that will measure 24 Vdc. Step 3. Disconnect lead 75 input voltage from stoplight switch. Step 4. Touch positive lead of multimeter to contact end of lead 75. Step 5. Touch negative lead of multimeter to frame ground. a. Voltage should be present. If voltage is present, go to test 2. b. If voltage is not present, go to malfunction 17, test 3, depress brake pedal, and check pin A. Test 2. Check stoplight switch for output voltage. Step 1. Set multimeter to a voltage range that will measure 24 Vdc. Step 2. Disconnect output lead 75 from stoplight switch. Step 3. Touch positive lead of multimeter to contact end of stoplight switch. Step 4. Touch negative lead of multimeter to frame ground. Step 5. Depress brake pedal. NOTE If vehicle is equipped with hydraulic stoplight switch and switch is defective, replace with air-activated stoplight switch conversion kit, part number 12255668. If voltage is not present, replace stoplight switch (para. 4-29). 2-116