TM9-4120-370-14
TO35E9-229-1
4-53. HEATER RELAY (K1) -
Continued.
(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
(1) Use a continuity tester or a Multimeter set on the lowest OHMS scale to check continuity between terminals
A1 and A2, B1 and 62, 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.
(3) Apply 24 volts dc across terminals X1 and X2 and repeat continuity checks between terminals A1 and A2,
B1 and B2, and C1 and C2. All three contacts should be closed. If there is no continuity, replace the relay.
(4) Remove the 24 volts dc from the coil terminals X1 and X2.
Installation
d.
(1) Place U type spring nuts on four mounting holes.
(2) Using screwdriver, secure relay with four screws.
(3) See tags and wiring diagram (Figure 4-20) and connect wire leads.
(4) Remove tags.
(5) Using a screwdriver, secure junction box cover with ten screws and lock washers.
Install junction box. (See para 4-45.)
Follow-on procedure:
Remove junction box, (See para 4-45.)
Preliminary procedure.
4-105