Test the blue harness in the same manner, except plug connector W5P1 of the harness into J1 connector (left
side) on switch box, toggle switch S33 to "blue", and exercise switches S1 through S12 on left side of panel. Record
readings. Pass value is ten (10) megohms or greater..
(10) After completion of exercising switches S1 through S12 for the blue harness, the test is complete. Failure
of any of the 12 switch positions is cause for rejection of harness. See paragraph 9 for correction procedures.
(11) If either blue or yellow harnesses are serviceable, reinstall harnesses on engines per TM 55-2840-248-23,
(12) Perform checks per TM 55-2840-248-23, Table 1-11.
9. Correction Procedures
. If any
of the insulation resistance readings fall below the minimum indicated pass values,
proceed as follows:
a. Clean the connectors per TM 55-2840-248-23, Appendix H, paragraph H-11, using isopropyl alcohol. (Refer to
b. Allow the connectors to air dry for a minimum of one hour prior to retesting.
d. If any of the insulation resistance readings still fall below the minimum indicated pass values, proceed as
(1) For the yellow harness, the aircraft shall be grounded until a new harness is installed.
(2) If any blue harness pin insulation resistance falls between 1 megohm and 10 megohms, the aircraft may
continue to fly. Replacements, however, are still required and shall be made upon receipt. Units who have blue
harnesses with pin values below 1 megohm shall phone the Technical Point of Contact(s) for further instructions.
10. Supply/Parts and Disposition.
a. Parts Required. Items cited in paragraphs 6 and 7 may be required to replace defective items.
b. Requisitioning Instructions. Requisition replacement parts through normal supply channels using normal supply
c. Bulk and Consumable Materials.
TT-I-735, Grade B
d. Disposition. Dispose of removed parts/components in accordance with normal supply procedures.
e. Disposition of Hazardous Material. Not applicable.