TM 9--2350--292--20--1
0018 00--7
AUXILIARY POWER UNIT FAILS TO CRANK -- CONTINUED
0018 00
O
Is continuity present?
CONTINUED FROM STEP N
no
yes
P
Is continuity present?
no
yes
Q
Is continuity present?
CONTINUED ON NEXT PAGE
1. Reconnect harness 3W711 P1 at APU
engine disconnect.
2. Disconnect harness 4W700 P1 at APU
control box.
3. Disconnect harness 4W700 P2 from
bulkhead disconnect.
4. Place multimeter red lead to harness 4W700
P2 pin B and black lead to harness 4W700
P1 socket A.
5. Check for continuity.
Repair (WP 0290 00) or
replace (WP 0332 00)
harness 4W700. Verify
fault is corrected.
1. Place multimeter red lead to harness 4W700
P1 socket C and black lead to ground.
2. Check for continuity.
Repair (WP 0290 00) or replace
(WP 0332 00) ground lead from
control box connector to ground.
Verify fault is corrected.
1. Remove control box rear panel (WP 0247 00).
2. Turn PREHEAT switch to MOM ON
(TM 9--2350--292--10).
3. Place APU GEN switch to OFF.
4. Place multimeter red lead to control box
harness 4W725 pin A and black lead to pin C.
5. Check for continuity.
no
yes
Go to step AA.
