TM 9-4120-388-14
This task consists of: a. Removal
b. Inspection
c. Test
d. Installation
INITIAL SET-UP:
Equipment Condition
Junction box cover removed (4-47).
Removal.
a.
(1) Tag and disconnect wire leads.
(2) Remove four lock nuts from relay.
b. Inspection.
(1) Check for loose, corroded, missing, or broken terminal connections.
(2) Check relay for cracks, evidence of overheating, and other visible damage. Replace if damaged.
Test.
c.
(1)
Use continuity tester or a multimeter set on the lowest OHMS scale to check continuity between terminals (A1
and A2, B1 and B2, and C1 and C2). All three contacts should be open. If there is continuity, replace the relay.
(2)
Check continuity between coil terminals (X1 and X2). If there is no continuity, the coil is open. Replace the relay.
Apply external 24 volts DC power across terminals (X1 and X2) and repeat continuity checks between ter-
(3)
minals (A1 and A2, B1 and B2, and C1 and C2). All three contacts should be closed. If there is no continuity,
(4)
Remove the external 24 volts DC power source from coil terminals (X1 and X2).
4-104