Nav Instruments Wiring 411
Hello all - I am in the midst of troubleshooting a total outage on my nav instruments. Could be lightning, could be overvoltage from a malfunctioning charger (put out 16.8 volts), not sure yet - all I know is they worked, now they don't, all instruments are dead. I checked the main breaker, it is functioning, and when on, puts 12 VDC to the hot lead, which disappears into the starboard space behind the panel with a big trunk of wires. I will find it sooner or later, but hopefully someone else already knows - where is the terminal board or whatever Swan used to bring the instrument leads and power together into the connector-terminated cables that go to each display and repeater. The instrument suite is B&G Network - I don't know if it is original or not. Has anyone chased this system down, and can you tell me where the power lead and leads from the mast hook up are connected in, by terminal board or splice or what have you? Any guidance might save me time, which would be appreciated.

Thanks,

Geoff

Corazon
Swan 411 #41

Hi Geoff,

any news on your instruments?

Regards,
Christian 411/28

Christian:

So far, no - but that is due to my putting it off, and the fact that I can sail pretty well without them when I'm in my regular area, where I know the depths well. I do intend to get to the bottom of it this week, however, and will report back to the forum what I find.

Thanks -

Geoff

Corazon, 411 #41

Hi Geoff, any news on your instruments? Regards, Christian 411/28

I finally can report what happened - although I am a little embarrassed to say. The problem was that the crimp-on connector, screw eye type, on the instrument side of the breaker, was poorly crimped, and there was corrosion inside there too, so continuity was poor.

When I had interrogated the voltage there, it showed proper voltage, indicating the breaker was working, and also, so I thought, that power was available in the wire itself - but there was no power at the instruments, which led me to think there was a fuse or break somewhere in between, maybe where the 12V lead spliced to the B&G cabling. Anyway, I never found the problem, so I sailed without my instruments all summer, which was fine, except I like to have depth readings, plus I like everything aboard to work, but to make a long story short, when I got the boat to her winter yard, I asked the guys there to look at that circuit again. They might have burned a lot of time looking, except I got lucky, because they happened to be watching the panel when they bumped the lead in question and saw the instrument show a reading right then - so they knew the problem was right there. From the outside, the wiring looked sound, but it wasn't - which is a lesson learned. I still did not expose the transition or splice from the 12V power lead to the connectorized B&G cabling, but I will leave that for another time. Anyway, that's the story.

Fair Winds,

Geoff
Corazon, 411 #41