power to autohelm

[garyw]

Hi

I just had my auto helm an st 4000 raymarine model repaired because of a sea talk error message but now don't seem to be getting any power to the unit.  As someone who is not that familiar with electrical matters,  what would be the best way to trace the wire which is inaccessible and hard to see.  I have tested the wire coming into the unit for voltage and there is none so I suspect that I blew a fuse somewhere in the wire.    The other instruments on the pedestal, are getting power and I think the auto helm has it's own power cord that comes into it.   The electrical wires behind the electrical panel is a rat's nest of wires so I suspect I should start there.   

Thanks

Gary W
Summer Wind 
Catalina 34   1986

[Stu Jackson]

Gary, it would be much easier to start at the other end.  Find out where the power wires come from the autopilot and begin tracing them back to the panel.  How do you turn the power on to the ap?  Which switch/breaker?  That will be where they end in the panel, regardless of the rat's nest.  Then, while you're doing this, label that wire.  Every time you're in there, label another wire and eventually you'll get them all.