CORRECTIVE ACTION Continued
Reconnect APU control box to foot dimmer switch and bulkhead wiring harness to 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 F of wire 421 and black lead to
ground. Turn MASTER and APU fuel shut-off switches ON and check for voltage. Turn MASTER
and APU fuel shut-off switches OFF. If voltage is present, go to step 10. If voltage is not present,
repair/replace wire 421 of APU control box to foot dimmer switch and bulkhead wiring harness (see
WP 0228 00 for dual voltage; 0229 00 for single voltage).