Seiwa SW AP01 - Manual (Page 47)

Conditions which can cause the alarm to appear are if the transducer is off-centre by
more than 10 deg. or the autopilot rudder limit has been set beyond the mechanical
limit.
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4.3 OTHER FAULTS
The Junction Boxes contain over-voltage protection circuits. If there are large voltage
spikes on the power supply, the system may shut down and re-start without an error
message appearing. If this happens frequently, consult your dealer about measures to
filter the supply.
If the system will not switch on, check the main fuse and second fuse, if fitted. Using a
voltmeter, check that the correct voltage is applied to the two power terminals and that
the polarity is not reversed. A voltage of about 6V should also appear on the blue
Controller lead when the system is off. If these conditions are correct, disconnect all
cables except the power and Controller and try to switch on. If the self-test message
now appears, the fault is in one of the attachments. If these tests do not reveal the
problem, another possibility is that the program store (EPROM) has not been fitted
correctly or that a pin is bent or broken. If that is not the problem, a service call is
required.
The steering drive transistors are electronically protected, but can be damaged by
extreme stress. The common symptom is that the steering will drive one way and not
the other. Other types of damage can cause the main fuse to blow when the system is
switched from STANDBY to PILOT. In such cases, the Junction Box should be
returned to your dealer or to Coursemaster for repair.
4.4 FUSES
The system has two fuses. The main 20A fuse protects the complete system, while a
0.8A miniature fuse (See Figs 3.1 and 3.2) protects the control electronics against
supply surges.
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