APU CONTROL BOX JUMPER WIRES AND TIMER HARNESS (CONT)
8. Remove one nut (15), lockwasher (16), and washer (17) and remove timer harness (12).
Inspect APU control box jumper wires for missing or unreadable wire markers. If defective, apply new markings
or replace wire markers. Use APU electrical schematic (figure FO-4) as a guide for proper wire markings.
Inspect APU control box jumper wires and timer harness for frayed or broken wires and loose terminal lugs. If
defects exist, use electrical repair kit and replace defective terminal lugs, jumper wire assembly, or timer harness.
Refer to appendix F and, using electrical repair kit and measuring tape, fabricate new APU control box jumper
wires as required.
Using wire stripper, strip wires to designated length to allow for terminals to be installed.
Using electrical repair kit, crimp terminal lugs onto fabricated jumper wires as required.
On APU with APU engine serial number 504697 and subsequent, the glow plug
indicator is changed from a glow-type indicator to a lamp driven by a timer.
On lamp-type glow plug indicator, install ground wire on timer harness (12) and secure using screw (18), timer
(13), washer (17), lockwasher (16), and nut (15).
Plug timer harness (12) into timer (13).
Using APU electrical schematic (figure FO-4) as a guide, connect tagged timer harness wires (12) to starter
switch (7) terminals GL and ST.
Plug timer harness wires (12) to glow plug indicator (14) wires.
Slide a 3-inch (7.6 cm) piece of heat shrink tubing over quick-disconnect plug on APU wiring harness (9).
Using APU electrical schematic (figure FO-4) as a guide, reconnect diode (8) to jumper wire (6). Reconnect
jumper wire (6) to starter switch (7) terminal B.
Reconnect open end of diode (8) to existing APU harness wire (9).
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