TM 9-2320-361-20 Table 2-3. Compressed Air and Brake System Troubleshooting (Contd). MALFUNCTION TEST OR INSPECTION CORRECTIVE ACTION 16. AIR HORN DOES NOT WORK Step 1. Refer to electrical troubleshooting malfunction 38. Step 2. If malfunction still exists, refer to malfunction 9, test 2, steps 1-4. NOTE Air pressure gage on instrument panel has a maximum pressure scale of 120 psi. If old governor has been replaced with new governor, air pressure may exceed maximum pressure reading on instrument panel gage. If air pressure reading of test 2 is comparable to air pressure gage on instrument panel, replace air horn (para. 4-31). END OF TESTING! 2-73