Green Wire Connection

Electrical and electronic topics for small boats
Fuzzy748
Posts: 2
Joined: Wed Jun 12, 2019 3:30 am

Green Wire Connection

Postby Fuzzy748 » Wed Jun 26, 2024 8:59 am

Q1: on a [Boston Whaler boat of unknown model year] RAGE model [of unspecified length] with 115-HP [jet drive] where does the GREEN wire connect to the engine?

BACKSTORY
While reinstalling the 115-HP engine into my RAGE boat, I failed to remember where the GREEN conductor attaches to the engine.

I’ve attached the red [conductor from the] positive [terminal of the starting battery] to the starter solenoid, the black [conductor from the starting battery] negative [terminal] to the starter [motor] casing bolt. But I cannot remember where the green "earth" wire goes. [The green conductor is] attached to the battery negative [terminal] in the console. It runs along with the other cables and looks like it should attach somewhere on the Port of the engine.

[Moderator's note: moved to SMALL BOAT ELECTRICAL for discussion. When asking about a specific boat, be sure to include the model year using FOUR DIGITS, the model name, and the length dimension used in the model name.]

jimh
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Location: Michigan, Lower Peninsula
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Re: Green Wire Connection

Postby jimh » Wed Jun 26, 2024 10:19 am

Generally a GREEN conductor is used as part of a BONDING system. On Boston Whaler boats that have below-deck metal fuel tanks and have metal fuel inlet fittings, a 10-AWG conductor with GREEN insulation (or sometimes with YELLOW insulation) connects to the all the metal fittings of the fuel system, usually the fuel filler fitting, the metal fuel tank, and then connects to an isolated, external ,metal anode (often bronze) on the hull mounted on the transom below the water line.

If there were no dedicated and isolated anode on the transom, the bonding system would connect to engine chassis and thus to the gear case metal, which would be submerged below water when in operation and would have its own anodes (usually zinc). But the circuit of the GREEN conductor would NEVER connect to any other part of the boat that was also connected to the battery negative.

On a RAGE with a water-pump jet drive, I don't know if there would be some part of the jet drive that was always in contact with the water that might have been used for the GREEN conductor.

IMPORTANT--the BONDING system should NOT connect to both the engine chassis and the battery negative. If the GREEN conductor is connected to the battery negative and to the engine chassis, then it is connected to the battery negative in two places, because the engine chassis is always connected to the battery negative (by the large main black conductor). That is not how a bonding conductor is supposed to work. If connected to the battery negative and also to something else connected to the battery negative (the engine chassis) then there will be CURRENT flowing on the GREEN conductor.

My best guess is the GREEN conductor must connect to some part of the jet drive system that is below the water line all the time, and may (or should) not be connected to the engine block.

Q2: is there any other component in the area that the GREEN conductor could reach that is not already connected to the battery negative terminal that is part of the fuel system?

ASIDE: a good plan when disconnecting electrical wiring is to make a clear and well labeled diagram of the wiring and to also take color photographs of the wiring to help memorialize the initial wiring routes and connections. With a modern digital camera as part of every cellular telephone these days, taking those pictures is quite easy and painless.