TM 9-4120-378-14
4.25 JUNC TION BOX. - Continued
Remarks
Action
Location/ltem
Heater Relay
(K2) (both mod-
els), Compres-
sor Motor Relay
(K3) bothmod-
els) , Condenser
Fan Motor
Relay (K4)
(model)
A9KH-115P)
Tag and disconnect wire leads.
a.
Inspection
See fig. FO-1. through
Use a continuity tester or multimeter. Set on the
b.
fig. FO-4.
lowest ohm to check continuity between termi-
nals Al1to A2, B1 to B2, and C1 to C2. All con-
tacts should be open. If there is continuity, re-
place the relay.
Check continuity between terminals X1 and X2.
c.
If there is no continuity, the coil is open. Replace
the relay.
Apply 24 volts DC across terminals X1 and X2
d.
and repeat continuity checks between terminals
Al and A2, B1 and B2, and C1 and C2. All three
contacts should be closed. If there is no continu-
ity, replace the relay.
See FO-3 and Fig FO-4
Tag and disconnect wire leads.
a.
Condenser Fan
Motor Relay
Use a continuity tester or multimeter, set on low-
b.
(K4) (Model
est ohm scale, check continuity between teminals
F9000H-1S)
1 to 3, terminals 5 to 11, and terminals 8 to 10.
All contacts should be open. If there is continuity,
replace relay.
Check continuity between terminals 2 and 9. If
c.
there is no continuity, the coil is open. Replace
the relay.
Apply 24 volts dc across terminals 2 and 9. Re-
d.
peat step b., above. All three contacts should be
closed. If there is no continuity, replace relay.
Control Circuit
Breaker
See fig. FO-1. through
Using a continuity tester or a multimeter set on
Inspection
a.
fig. FO-4.
the lowest ohms scale, check continuity between
terminal contacts 1 and 2.
In the OFF position, no continuity should exist.
b.
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