NAVELEX EE181-AA-OMI-090/E121 SA-1954
d. If voltage to Control Unit is good, check
wires for open circuits and shorts-to-
ground in accordance with steps in
e. If voltage on wires is normal, replace
(1) To remove PC board, remove screws
that secure the PC board to the
relay bracket. Tag the wires,
and use a soldering iron of 50
watts maximum to remove them
from the PC board terminals.
(2) To replace PC board, use a soldering
iron of 50 watts maximum to
solder wires to PC board terminals.
Secure PC board to relay bracket
b. Bad system
a. Set multimeter to ohms and check from
TB1-9 to chassis and conduit. Meter
should indicate 0 ohms.
b. If meter does not indicate 0 ohms, check
ground and conduit connections to
ensure that they are clean and tight.
c. Set multimeter to ohms and check be-
tween TB1-8 and pin 3 on PC board.
Meter should indicate 0 ohms.
d. If meter does not indicate 0 ohms, check
TB1-8 and pin 3 on PC board to en-
sure that connections are clean and
c. Bad PC board.
a. If switch S1 is good, set multimeter to
ohms and check between TB1-1 and
pin 4 on PC board. With switch S1
in the normal position (no alarm),
meter should indicate 0 ohms.
Operate S1, and meter indication
should change to infinity.