Earth Cables in Engine Area

[stevd]

I had my engine removed by the yard engineer so that I could re-build it. I have had to re-install the engine myself, as I am unable to get the yard engineer to do it for me.

I didnt watch the engine being removed, so I had no idea what all the mess of cabling left behind was for. I have rewired the engine so that it works with my basic understanding. But I also have a lot of earthing cables in the engine area. It is a bukh dv20. Are the earth cables for annodes or what? I have a galvanic isolator on the boat. I am unable to work out where these go to. Any ideas on what they could be for?

Also, where do most people run the battery negative to, an engine mount? Mine has a half loop on it, it was a full loop but it seems to have been broken somewhere down the line. Like a lot of the connectors :-(

 

[prv]

You could well have a cable from an anode to the engine or the gearbox, but I wouldn't expect there to be "a lot".

Any answers here will just be guesses. We can't magically trace your wiring from a distance. You will have to get on and follow the cables to see what the other ends are attached to.

For hidden wiring, you can buy a tool which clips onto one end of a wire and makes it radiate a tone frequency. You can then follow it - without touching or needing to see it - with the other half of the tool which is a thing a bit like a small metal detector. I bought a cheapo Chinese one for a few quid. However, my point is that in almost completely rewiring a 34-foot boat, I never needed to use it. I could identify everything by following it with eyes or fingers, by a process of elimination, or by pulling it and seeing what moved.

Pete

 

[Billjratt]

Logically, if they are in the engine area, and the engine was the only thing that was moved, you would expect them to connect to it...
However they may not be doing anything any more. You don't say how old the boat is, but I'd be surprised if there aren't a few obsolete ones.
Maybe you should just see what doesn't work anymore and take each case as it happens.
Don't know Bukh but assume it's not isolated.