ComNav 1500 - Page 58

ComNav 1500 / 1510 Autopilot - 51 -
SYMPTOM CAUSE ACTION
Motor Pumpset turns but the
rudder doesn’t move.
Pumpset drive section in
Distribution Unit may have failed
to open.
Replace transistors, integrated
circuits or entire circuit board.
Broken or loose motor coupling Replace or tighten coupling as
necessary.
Pumpset contamination. Clean or replace Pumpset.
Low battery voltage. Automatic
shut-off in case of voltage lower
than 10.5V for 12V battery and
21.5V for 24V battery.
Turn Autopilot off and charge
batteries or correct voltage loss.
When proper voltage restored,
restart Autopilot.
Poor wiring connection. Check for voltage drop and repair.
Power wiring is undersized. Replace wiring with correct gauge.
Blinking [Low Bat] on bottom
line of display.
Voltage drop across circuit
breaker.
Make sure 25Amp circuit breaker is
used.
APC routine not performed. Pilot calibration “APC” required.
Power transistors in Distribution
Unit may be shorted.
Replace transistors or entire circuit
board.
Rudder Transmitter linkage
disconnected.
Re-connect and align as per
Installation Instructions.
Rudder Transmitter wiring
shorted or open circuit.
Check and repair wiring as
necessary.
When Autopilot engaged,
rudder goes hardover.
Rudder Transmitter pot
defective.
Replace.
Autopilot wanders on some
headings.
Magnetic interference is present.
The worst steering is usually on
northerly headings in the
northern hemisphere and
southerly headings in the
southern hemisphere.
Perform Auto-Deviation-Clear [CLR]
and Auto-Deviation [DEV] again, or
try another compass location.
Investigate for magnetic
disturbances around compass, e.g.
Masses of steel, motors,
loudspeakers, etc.
Severe magnetic interference. Choose another compass location.
Air in hydraulics. Fill and purge the steering system.
Slack in the steering system. Repair any loose or worn parts.
Autopilot wanders on all
headings.
Rudder Transmitter
potentiometer is “noisy” or
intermittent.
Replace rudder potentiometer.
Compass damaged; intermittent
wiring connections.
Repair any loose or worn parts;
recheck and connect wiring.
Slow wander means rudder
control is set too low
(understeering).
Increase Autopilot setting [P1] [RUD]
Fast wander means rudder
control is set too high
(oversteering).
Decrease Autopilot setting [P1]
[RUD]
Excess rudder load. Reduce rudder friction, increase
steering cylinder size, increase
power of the Pumpset.
Rudder movement erratic.
Air in system. Check for leaks and bleed the
system.