TM10-3930-660-20 Table 2-2. Electrical  Troubleshooting  (Cont’d) MALFUCTION TEST OR INSPECTION CORRECTIVE  ACTION Step 2. Step 3. Step 4. Check if circuit breaker (CB7) is tripped. l The circuit breakers will trip if there is a shorted or grounded wire. l The  circuit  breakers  will  automatically  reset  after  cooling.  They cannot be reset manually. l Under  normal  operating  conditions,  circuit  breakers  should  never require replacement. However,   if a circuit breaker does not reset after it has cooled, the circuit breaker is defective and must be replaced,  para.  8-12. Check circuit for shorts, broken wire, or bad ground. Refer to electrical schematic, page F/O-l. Check for bad ground connection, broken wire, loose connections, or faulty floodlight assembly. Test floodlight assembly and wires for continuity, para. 8-46 and 8-47. Replace if defective. Check for defective light switches. Test for continuity in boom, front, and rear, floodlight switches. Replace switches if defective, para. 8-8. WARNING  SYSTEMS 11. HORN DOES NOT SOUND Step 1. Check if circuit breaker (CB10) is tripped. l The circuit breakers will trip if there is a shorted or grounded wire. l The  circuit  breakers  will  automatically  reset  after  cooling.  They cannot be reset manually. l Under  normal  operating  conditions,  circuit  breakers  should  never require replacement. However, if a circuit breaker does not reset after it has cooled, the circuit breaker is defective and must be replaced, para. 8-12. Test circuit for shorts, broken wire or bad ground. Refer to electrical schematic, page F/0-l. 2-17