Originally Posted by Erin
The negative post on the battery is not a true 'ground'. To achieve this you would need a proper ground plate fitted to the hull to allow static discharge to the sea. Connecting everything together and linking to the neg post on the battery will not earth the items and may also create corrosion. As Martini stated, his is connected to an anode which will limit corrosion and also act as a partial ground.
Depending on your sender type, the two wires running to it may also not be connected to 12v or 0v but may be just a loop out of the gauge sensing resistance.
Erin, the grounding issue makes sense.
Just one question though. Please don't take this the wrong way, I am just trying to learn as I have recently completed wiring my new 6m rib with a Suzuki DT200 and was hoping I had it right.
I am confused. Assuming that:
(1) The fuel sender (and fuel filler) is connected to the -ve post of the battery;
(2) the engine is connected to the -ve post of the battery;
(3) the engine has an anode as most outboards do.
Will the anode not act as the grounding plate and since it is the least noble metal, will it not limit corrosion elsewhere?