TM 9-2320-361-20 4-31. AIR HORN, SOLENOID, AND BRACKET REPLACEMENT (Contd) 3. Connect air line (2) to elbow (3). 4. Connect wire plugs (5) and (6) to air solenoid (4). FOLLOW-ON TASKS: Connect battery ground cables (para. 4-48). Start engine (TM 9-2320-361-10) and allow air pressure to build up to normal operating range. Check for air leaks at horn solenoid. Check horn for proper operation (TM 9-2320-361-10). 4-49