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  1. #1
    Cadet
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    Default 76 Mercury Wiring Diagram

    I am in desperate need of a 76 Mercury 85hp (or 850) 4 cylinder outboard wiring diagram. The engine harness fryed and I can't tell what wire goes where or even what color they are. I just bought a new harness and there are just a few of the wirings that I don't know where they go. I have the soleniod and electric choke wires figured out. The serial number 4232325. Thanks.

  2. #2
    Supreme Mariner
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    Wink Re: 76 Mercury Wiring Diagram

    OK, That motor is distributorless, so orange is the killer wire that attaches to the switch boxes and mercury switch. White is not used(for distributor motors), red goes to the switchboxes, small black wire is the ground on the starter solenid. Grey is choke solenoid, brown is tach signal and yellow/red is stator for battery charging.

  3. #3
    Cadet
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    Default Re: 76 Mercury Wiring Diagram

    This motor has a distributor.
    The new harness I purchased has a color coded instruction sheet included in the box. All the original wiring insulation is burnt off or has changed color because of the heat that even with the color coded instructions I still don't know exactly where the wire goes. I have figured out the solenoid wiring and the electric choke but the wires that go to the ignition box or whatever you call it has got me at a loss. I see that the terminals on the box are different colors (red terminal, white terminal, brown and so on). What I need to know is which wire went on which colored terminal on the box. Sorry for the confusion, I'm new to boat engines and I hate wiring. Thanks so far.

  4. #4
    Rear Admiral Plainsman's Avatar
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    Default Re: 76 Mercury Wiring Diagram

    Rest in Peace Spinner

    2010 Lowe FM 175 with a 2010 115 Mercury
    ------------------------------------------------
    Your friend,your partner, your defender,your dog.You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion....by E.F. Henry

  5. #5
    Cadet
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    Default Re: 76 Mercury Wiring Diagram

    Thanks Plainsman! That should do it. Thanks a bunch!

  6. #6
    Supreme Mariner
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    Cool Re: 76 Mercury Wiring Diagram

    The wiring diagram provided is for the distributorless ADI Ignition. I hope it works for you.

  7. #7
    Petty Officer 2nd Class
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    Default Re: 76 Mercury Wiring Diagram

    For what it's worth850 001 (Medium).jpg

    850 002 (Medium).jpg. 850 wiring pics.

  8. #8
    Rear Admiral Plainsman's Avatar
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    Default Re: 76 Mercury Wiring Diagram

    1975 has a distributor, according to your serial number it's a 1975, not a 1976.

    Rest in Peace Spinner

    2010 Lowe FM 175 with a 2010 115 Mercury
    ------------------------------------------------
    Your friend,your partner, your defender,your dog.You are his life, his love, his leader. He will be yours, faithful and true, to the last beat of his heart. You owe it to him to be worthy of such devotion....by E.F. Henry

  9. #9
    Supreme Mariner
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    Cool Re: 76 Mercury Wiring Diagram

    OK, so you have a distributor. Yellow-red wires run from the stator terminal block to the AC poles on the rectifier. One of these AC terminals connects to the brown wire to provide a signal to the tach. yellow is the starter solenoid primary +12V terminal, grey is the choke solenoiod, orange is unused, thick black is grounded to the bottom cowl, thin black is ground on starter solenoid primary-12V terminal, thick red is +12V on the starter solenoid secondary. Thin red goes to the red terminal on the switchbox, thin white goes on the white terminal of the switchbox (the red and white terminals are on the same side(starboard) of the switchbox). The +12V side of the rectifier gets a red wire which connects to the other red wire. The -12V pole on the rectifier (if rectifier is aftermarket) is grounded to the case.

  10. #10
    Commander ricksrster's Avatar
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    Default Re: 76 Mercury Wiring Diagram

    oops
    "Many of the greatest sailors were pukers."--Thorfinn Skullsplitter

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