Source of Electrical Bonding of Rudder Post to Ground

[rardiH36]

I recently noticed in Don Casey's "Sailboat Electrics Simplified" that just like bronze through-hulls, its generally best that the rudder post be isolated from the ground to minimize corrosion.

Checking my rudder post today, the continuity tester between it and the engine block sounded.

Before I go looking for the source of the electrical connection, does anybody know if Hunter bonded the steering system?

I don't think that any of the electronics in my pedestal (just the compass light and the Raymarine Autopilot) are the culprits -- but that will be checked.

Thanks,
rardi

 

[Ed Schenck]

That's a real surprise, "shocking" in fact! But with the post attached to the radial wheel which has cable to the pedestal and . . . . So I can see where it is possible. Removing the cable and checking again might prove something.

 

[Ed A]

I wonder if your meter is set for to sensitive a setting.
check the water over several feet, maybe your measureing the conductivity of the sea water?

 

[Blaise]

I am not an electrician, But I can tell you for sure that there is no electrical gound on the rudder, since I just replaced mine. I believe you are reading continuity between the engine and rudder because the rudder shaft is in contact with the seawater, and the engine is in contact with the seawater by way of the propeller shart. I am sure that almost everone else knows more about this than me, so I would like to hear an educated answer how this could occur.

 

[rardiH36]

Blaise, thanks the info that you don't have rudder post grounding . I'll investigate what might be happening the next time I'm on the boat. It's gotta be some ground wire to the pedestal that is transferring through the chain/cable/quadrant to the rudder post. But as I mentioned in my opening post, all I've got on/in the pedestal that I know of is the compass light and the power to the Raymarine autopilot motor. And actually, I did disconnect the quick plug from motor and still registered the continuity.

Regarding the continuity tester (one of the positions on my multimeter), I suppose its possible that the "continuity" is through the sea water. But in the past, I do know that only a few ohms of resistance is enough that the audible continuity sound doesn't happen.

 

[rardiH36]

Gotta Be The Morse Throttle/Gearshift Cables

Checking today, the source of ground "bonding" between the rudder post and the engine common ground is not from any electric wires.

So the only other explanation is the Morse shift and throttle cables. When I first bought my 1980 Hunter with the original Yacht Specialties pedestal/steering, I did modify the shift/throttle housing part on the top of the pedestal because I had read that the Morse cable anchor points in the the old plastic were prone to break apart. It is possible that my mod has caused the metal Morse cable sections to come in contact with pedestal metal. So ground transfers from engine to pedestal to rudder post. When I have the time, I'll take the pedestal parts apart and fix.

rardi