TM 9-2320-209-20-3-3 18-72. 24-VOLT DOME LIGHT AND BLACKOUT DOME LIGHT TOGGLE SWITCHES REMOVAL AND REPLACEMENT (TRUCK M109A2 AND M109A3). TOOLS: Flat-tip screwdriver 9/16-inch wrench SUPPLIES: Tags PERSONNEL: One EQUIPMENT CONDITION: Truck parked, engine off, handbrake set. a. Preliminary Procedure. Disconnect battery ground cable. Refer to Part 1, para 7-58. 18-380