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Yanmar 3GM30F - What are these wires for

Discussion in 'Big Boats' started by sailcapt340, Aug 28, 2017. Add this thread to a FAQ

  1. sailcapt340


    Joined Sep 26, 2008
    130 posts, 3 likes
    Hunter 340
    US Wickford, RI
    On my 2000 Hunter 340, with Yanmar 3GM30F Engine. I have two wires, with bayonet connectors attached, that are not connected to anything.
    They never have been since I bought the boat new in 2000. They are simply hanging there.
    They come out of the wiring harness from the starter motor.
    What would they have been used for that I didn't get when I purchased the boat? There has to be some piece of equipment or gauge I don't have.
    I figured someone with the same boat has them connected to something.
    Thanks for any help

  2. stuartsw


    Joined Sep 22, 2009
    69 posts, 7 likes
    Hunter 36
    US Seattle, WA
    Do you have a fire suppression system with a sensor for the engine compartment? It is possible that those are the wires for the sensor.

  3. sailcapt340


    Joined Sep 26, 2008
    130 posts, 3 likes
    Hunter 340
    US Wickford, RI
    No....I don't have that. It has to be for some gauge or diagnosing equipment. Just don't know what. I'm hoping someone has something plugged in to it.

  4. MitchM


    Joined Jan 20, 2005
    529 posts, 57 likes
    Nauticat 321 pilothouse 32
    US Erie PA
    yan mar has diagnostic plugs on a number of its engines so their shops can figure out what's going on .

  5. Sailgunner


    Joined Jun 4, 2004
    793 posts, 20 likes
    Hunter 410
    US Punta Gorda
    Have similar wires on my 2000 410.

  6. artboas


    Joined Jun 1, 2009
    1,044 posts, 40 likes
    Hunter 49
    ca toronto
    Basic engine diagnostic philosophy
    Step 1
    Does it work?
    If "Yes"
    Step 2
    Don't mess with it

    justsomeguy likes this.
  7. sailcapt340


    Joined Sep 26, 2008
    130 posts, 3 likes
    Hunter 340
    US Wickford, RI
    By far that's probably the best "Diagnostic Meter" anyone can add to their tool box. They seem happy where they are.

  8. pateco


    Joined Aug 12, 2014
    1,676 posts, 364 likes
    Hunter 31 (1983)
    US Pompano Beach FL
    My 2 GM also has two hanging wires. I have no idea what they are for.
    The blue one in the picture below is one of them.
    2015-11-01 10.12.05.jpg

  9. Ryan and ileana Bradley

    Ryan and ileana Bradley

    Joined Dec 22, 2013
    11 posts, 1 likes
    Hunter 34
    US Oak Harbor
    I have the same engine and the same wires and connector! I looked into it it is for a sail drive, which I don't have so it just hangs there, so I tied it up so it doesn't flop around.

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