This test applies to lead 65 of APU wiring harness
Connect this lead to the starter relay of the APU.
Before beginning the test, be sure the MASTER switch is in the
OFF position. Disconnect lead 65 from the starter relay. Place
the multimeter red probe in lead 65 connector and ground the
black probe. Set the MASTER switch to the ON position and hold
the PREHEAT and START switches in the ON position (Figure 46).
If voltage is indicated, replace the starter relay as shown in TM
If no voltage is indicated, repair or replace
lead 65 from the starter relay to the main APU compartment
connector as illustrated in TM 9-2350-267-20.
If engine still
does not crank, proceed to Test 13.
APU Wiring Harness Lead 65 to Starter Relay.
This test applies to lead 66 of APU wiring harness
121429640. Connect this lead to the APU starter relay. Be sure
the MASTER switch is in the OFF position before beginning this
Reconnect lead 65 connector to the starter relay and
disconnect lead 66 plug. Place multimeter red probe in lead 66
plug and ground the black probe (Figure 47). Now set the MASTER
switch to the ON position. If voltage is not indicated, repair
or replace the APU harness lead 66 from harness plug to the
starter relay as outlined in TM 9-2350-267-20.
If voltage is
indicated, go on to Test 14.
Do this test on the opposite lead 66, on the outlet
side of the starter relay.
Ensure the MASTER switch is set to
the OFF position. Reconnect harness lead 66 to the APU starter
relay (Figure 12 and Figure