TM 9-2320-209-20-3-4 23-9. PERSONNEL AND ENGINE HEATER CONTROL BOX INDICATOR LAMP REMOVAL AND REPLACEMENT. NOTE This procedure is the same for the personnel and engine heater control boxes. This procedure is shown for the engine heater control box. TOOLS: None SUPPLIES: None PERSONNEL: One EQUIPMENT CONDITION: Truck parked, engine off, handbrake set. a. Removal. FRAME 1 1. Unscrew and take off lens cap (1). 2. Take out indicator lamp (2) by pushing it in and turning it to left. END OF TASK 23-22