CHAPTER 2: VEHICLE MAINTENANCE INSTRUCTIONSTM 9-2350-256-202-19 ELECTRICAL TROUBLESHOOTING-ContinuedAPU STARTING SYSTEM-ContinuedWARNINGRemove all jewelry such as rings, dogtags, bracelets, etc. If jewelry contacts ametal surface a direct short may result ininstant heatingof tools, damage toequipment, and injury or death topersonnel.DReconnect bulkhead to APU, master relay, and rigger'slights wiring harness to APU engine disconnect. Openair inlet doors (see TM 9-2350-256-10). Disconnectbulkhead to APU, master relay, and rigger's lightswiring harness from bulkhead disconnect. Place ajumper wire from pin B to socket B. Place red lead ofmultimeter in socket J of wire 65 and black lead toground. Turn MASTER and PREHEAT switches ONand check for voltage. Turn MASTER and PREHEATswitches OFF. If voltage is present, repair/replace wire65 of APU control box to foot dimmer switch andbulkhead wiring harness (see paragraph 6-79 for dualvoltage; 6-80 for single voltage). If voltage is notpresent, reconnect bulkhead to APU, master relay, andrigger's lights wiring harness to bulkhead disconnectand go to step E.EDisconnect APU control box to foot dimmer switch andbulkhead wiring harness from APU control box.Remove four nuts (1), four lockwashers (2), and fourscrews (3), and release APU control box (4) frommounting bracket. Remove four screws (5) and fourlockwashers (6), and release rear panel (7) from APUcontrol box. Reconnect APU control box to footdimmer switch and bulkhead wiring harness to APUcontrol box. Disconnect wire 65 from START switch.Place red lead of multimeter on terminal of STARTswitch and black lead to ground. Turn MASTER,PREHEAT and APU START switches ON and checkfor voltage. Turn MASTER, PREHEAT and APUSTART switches OFF. If voltage is not present, go tostep F. If voltage is present, repair/replace wire 65 ofAPU control box wiring harness (see paragraph 13-7).2-164
Integrated Publishing, Inc. - A (SDVOSB) Service Disabled Veteran Owned Small Business