Ground Behind Nav Station

Mark Erdos

Hi all,


I need a little help please from the electrical minded people please. I’ll be the first to admit most of what was posted regarding Ground and bond circuits on this forum is over my head (for now).


After reading Kent’s issue’s I am concerned since Cream Puff was also repowered with a Yanmar 4JH4-HTE and also has an 220v inverter installed. I am not sure if the inverter was factory installed or after market. While I hope the previous owner hired a mechanic/electrician that was schooled on Amel, I do not know for sure this was the case. Kent’s phrase “It is almost certain that my problem was caused by a combination of very poorly installed charger/inverter by a marine electrician and improperly bonded CDrive by the people who installed my new Yanmar.” has made me worry a little.


I recently found a circuit that doesn’t seem quite right. Behind the nav desk are the terminals controlled by the VHF/instrument breaker in the hanging locker. See picture by clicking above link. When I test for voltage between the pos(+) and neg(-), I get 24 vdc as expected. But, when I test voltage between the middle ground terminal and pos(+), I still get 24vdc. On the ground terminal is a green wire that goes to a Gnd on a 30 battery charger (exit bottom of pic), a green wire that goes to the Gnd on the Furuno heading sensor (exit top of pc) and 2 green/yellow wires (not sure where these go yet) connected to the terminal.


I was under the understanding the green/yellow wires were all part of the bonding system and not connected to the boat ground or neg(-) system. I removed the solid green wires and tested everything individually.


Terminal (+) and both green/yellow wires = 24 vdc

Terminal (+) green wire coming from battery charger (disconnected from terminal) = 24 vdc

Terminal (+) green wire coming from Furuno heading sensor (disconnected from terminal) = 24 vdc


Since my understanding that I stated above regarding green/yellow wires, I am seriously confused why I have a connection somewhere between the 24vdc neg(-) and these green/yellow wires. Any enlightenment would be greatly appreciated.




With best regards,




Super Maramu 2000

Hull #275


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