CORRECTIVE ACTION Continued
12. Reconnect APU control box to foot dimmer switch and bulkhead wiring harness APU control box.
Install APU control box (9), four screws (8), four lockwashers (7), and four nuts (6) to mounting
bracket. Open air inlet doors. Disconnect bulkhead to APU, master relay, and rigger's lights wiring
harness from bulkhead disconnect. Place red lead of multimeter on pin D of wire 493 and black lead
to ground. Turn MASTER and APU FUEL SHUTOFF switches ON and check for voltage. Turn
MASTER and APU FUEL SHUTOFF switches OFF. If voltage is present, go to step 13. If voltage is
not present, repair/replace wire 493 of APU control box to foot dimmer switch and bulkhead wiring
harness (see WP 0228 00 for dual voltage; 0229 00 for single voltage).