Black wire in the bilge

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dejavu's picture
dejavu
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Black wire in the bilge

I was cleaning the bilge today and found a loose black wire. It was apparently hose-clamped to one of the keel bolts and corroded and broke as the bare end is still clamped there. It looks like a ground wire. I had to leave & didn't have time to follow it back to it's origins. Is this standard or just something my PO installed? I intend to find the source then strip the wire and re-clamp it in place, but I was just curious if anyone knew.

Deja Vu
1991 MK I # 1106
Marina del Rey, CA

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Allan R
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Ground wire to the keel???

Allan Rex
# 2216

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LCBrandt
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If the wire was attached to a keelbolt it was probably the PO's mistaken attempt to find an electrical ground for some electronic system. I say "mistaken" because the keelbolts are embedded in the cast lead keel, with no direct (conductive) access to the exterior water, and lead is not a good conductor of electricity.

What gauge is the wire? Heavy? Light? Was there an HF installed at some prior point? Or perhaps the PO was trying to tie all metallic items together as a kind of lightning mitigation.

To answer your question, No, this is not standard. We'll be interested to find out where the wire goes.

Larry Brandt
S/V High Flight #2109
Pacific Northwest, PDX-based
2002 C-36 mkII SR/FK M35B
 

dwarburton
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I am guessing the wire goes to the mast step. I believe I have a connection from the mast step to the keel although I must admit I haven't paid it much attention.

Dave
Ballena 1995 Mk II #1445

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dejavu
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I'll trace it and report back. I'm too superstitious not to re-connect it, even if I can't figure out why it's there. Maybe it's been holding my keel on all this time. :eek:

Deja Vu
1991 MK I # 1106
Marina del Rey, CA

john hough
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If its not connected at one end and everything on board works, then take a wire from it to the batt neg through a continuity tester and see if it lights up. This would help let you know if its connected at the buss.

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ProfDruhot
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Mike, did you ever determine where that black wire originated from?

Glenn Druhot
Carpe Diem
New Bern, NC
35* 6' 10" N / 77* 2' 30" W
2001 C36, Hull #1965
Std Rig; Wing Keel; M35B

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dejavu
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[QUOTE=ProfDruhot;3193]Mike, did you ever determine where that black wire originated from?[/QUOTE]

No success yet. Looks like it goes toward the nav station. Followed it for a while, but then I lost it. :( I'm not done trying yet, just moved on to something else for the time being.

Deja Vu
1991 MK I # 1106
Marina del Rey, CA

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dejavu
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Update - Well, I followed it as far as I could toward the back of the electrical panel, then I lost it. I'm thinking it has to some kind of jury rigged lightning grounding wire. It's the only thing that makes sense to me unless you guys can think of something. I'm going to be ripping out the whole teak section and re-doing my nav station at some point. I'll be able to find it then. Think I should re-attach it to the keel bolt?

Deja Vu
1991 MK I # 1106
Marina del Rey, CA

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chooch
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Mike,
Did you ever run the continuity check John suggested?
Do you keep a simple multi-meter on the boat?
If so, you can use the meter to check the resistance between the negative terminal (or the negative buss on your switchboard) and the end of the mystery wire.
FIRST, however, I would use the meter in the DC Voltage setting to make sure there is no voltage present. Always safe to check first…
Then, check for resistance: High Ohms=open circuit, Very Low Ohms (or 0 Ohms) = continuity
If you find continuity, it was an attempt at another grounding attempt and not needed.
The engine is the main ground of the DC circuit and the prop and shaft provide excellent electron flow to the sea.
However, if you find an open circuit, then go back to your original plan to rip out the nav station; cause we don’t have a clue!
Enjoy…

Just a reminder:
The old color code for DC Negative (ground) was black.
The color code for 120V AC "Hot" line is also black (white is neutral and green is ground)
That's why the new gear has yellow wires for DC negative.
ALWAYS check for voltages if you are not POSITIVELY SURE you know what the wire is!

Fair Winds,

Glenn "Chooch" Jewell
Nautae Luna 1232 (RIP Tara 389 Hurricane Sally 2020)
GO NAVY - BEAT ARMY!

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