Green Ground wire from sender mounted directly to boat?

Hey folks,

New to boat wiring, and I notice that my boat has a green wire form the fuel sending unit that attaches directly to the boat just under the gas cap mount. From the reading I've done there shouldn't be any grounds to the boat since that could allow electrical current into the alumunim hull and cause a galvanic reaction with the water.

Is this correct?

The sending unit was wired with two other wires to the gauge. Three wires in total.

Should I simply remove the offending wire?
Leave it as is?
Route it somewhere else?

Thanks!:joyous:

Re: Green Ground wire from sender mounted directly to boat?

It is typical (and also likely required by ABYC practice) that all metal components of the fuel system be bonded together with a bonding conductor that typically will have green insulation and be of 8-AWG.

Cf.: https://law.resource.org/pub/us/cfr/ibr/001/abyc.E-01.1973.pdf

Re: Green Ground wire from sender mounted directly to boat?

^^ What he said ^^

I've owned 4 boats. Every one of them had a green bonding wire between the tank sending unit and the fill fitting.

Re: Green Ground wire from sender mounted directly to boat?

^^^ mine also has the bonding wire attached to the engine block (I/O engine)

Re: Green Ground wire from sender mounted directly to boat?

Thanks for the excellent feedback. The wire stays!

Re: Green Ground wire from sender mounted directly to boat?

All metal fittings should be bonded.

Re: Green Ground wire from sender mounted directly to boat?

Hi Rabid, You may have picked up on a recent comment by a member who suggested that an aluminum hull should not be connected to the negative because this might cause corrosion. There is a lot of misconception out there about grounding and bonding. We bond things together to ensure there is no chance of a voltage existing between objects. The parts of your fuel system are an example. There is always the possibility of an electrostatic voltage being produced even by the flow of gasoline through a fitting. Bonding the fittings to each other ensures that there can never be a spark developed that might ignite fuel vapours.

Unfortunately sometimes people assume that when you connect things such as the aluminum hull to the battery negative that the hull will now form part of a circuit that carries electric current. The comment made that I recall seeing indicated a concern that by connecting the hull to the negative, the hull would now be carrying current that would cause corrosion. It's only when one tries to use a bonded object such as the hull as a "return path" conductor instead of running a negative wire back to the battery that you have an objectionable current flow. Just connecting all the metal parts together and joining them to the negative causes no harm and is often a requirement. - Grandad