TM 9-2320-209-10-1 c. Shop Van and Instrument Repair Shop Trucks Controls and Indicators, 1. OPERATION BLACKOUT SWITCH 4. EXH. BLOWER switch. Controls 115V. -A. C. SYSTEM. Controls dome power to exhaust blower. lights in the 115 volt AC system. 5. Converter SELECTOR switch. Is 2. Circuit breaker box. Has four used to choose desired voltage. circuit breakers which control van body circuits. 3. POWER SWITCH 115V. -A. C. Controls all power to van body electrical cir- cuits except the 24 volt AC-to-DC converter for exhaust blower. 4-15