ARMY TM 9-4120-380-14
AIR FORCE TO 35E9-136-21
MODE SELECT SWITCH (S1) AND KNOB This task covers inspection, testing, repair/replace, removal and
Tool kit, service, refrigeration unit (Item 1, Appendix B)
Disconnect input power to the air conditioner before performing any internal
maintenance. Voltages used can KILL. Shutting the unit off at the control panel does not
disconnect unit power
(1) Disconnect air conditioner input power at source, and
Check that wire leads are properly connected to switch S1 and are not damaged (see fig FO-2 ).
b. Check switch (4) for smoothness of operation Replace switch if defective (see fig. 4-19).
Check switch (4) for signs of overheating or other visible damage If wires are damaged, replace as necessary
Check that knob (1) is not cracked or damaged
In this test, switch contacts are Identified by the wire number attached to the contact
Each wire is labeled with a wire number. Refer to fig FO-2 as an aid during testing
Set switch to each position m turn. Using multimeter, check continuity as listed m table 4-3 If conditions are abnormal at
any switch setting, replace switch.