ComNav 1420 - Fuse Replacement; Check the Fuse

ComNav Marine 1420 Autopilot System
Fuse Replacement
The 1420 Processor is protected against
reversed power connection by a fuse.
The fuse will blow if the power wiring is
reversed; but the fuse will usually not fail
otherwise.
So, if you ever do need to replace this
fuse, re-check your power supply wiring
for correct polarity.
To replace the fuse:
1. Turn off the power to the 1420.
1. Loosen the right side watertight
glands on the Processor, and
remove the end cap. Disconnect the
plugs.
2. Remove the 4 Phillips screws holding
the inner end cap. Remove the inner
end cap.
3. Bend up the copper ground tabs so
that they are parallel to the body of
the Processor.
4. Loosen the left hand side watertight
glands, and remove the outer end
cap. Disconnect the plugs.
5. Remove the four Phillips screws
holding the inner end cap.
6. Hold the left hand inner end cap.
Slide the Processor case to the right.
This will expose the circuit board.
7. The fuse is located on the top left
hand corner of the board. If it is
damaged, replace it with a
20 Ampere AGC fuse.
8. Reassemble the Processor by
working through the above Steps in
reverse order. Recheck your power
supply polarity before you insert
the power connector.
Check the Fuse
Do this before leaving the dock:
– turn on the Autopilot. Press the Red
and Green Keys
to move the rudder
(or outboard motor).
⇒ If the new fuse fails at this
time, you still have an
electrical problem on your
boat, or the Autopilot needs
repair.
Document PN 29010012 V1.3
40