Reading 5.0V off of rudder...is this my problem?

[C-J]

Reading 5.0V off of rudder...is this a problem?

On a tough streak in my new battery powered kayak, so out of ideas I took my voltmeter to it on dry land this morning.

When running the Minn-Kota trolling motor off of my 12V marine battery, I measured 5.0V off of the rudder, which the paint has flaked off of very quickly in the last month. That's with the negative lead of the meter connected to battery negative post, and positive meter-lead touching rudder. I get the nearly the same reading off of anything else conductive that is connected to rudder (like the wires running to my foot pedals for rudder control =4.5V).

With the motor off, no current leak like this.

Reading off of metal bits on motor = 2.8V.

I admit I know nothing about boat electricals...is this a problem? What can I do about it?

Anyone with some expertise?

Thanks in advance,

CJ

 

[C-J]

Diagnostic update: when I hosed the rudder/motor area off with fresh water...the voltage reading on rudder, wires, motor bolt is now up to 11.4V.

 

[Seafever]

Sounds kind of strange.......I have a Minn-kota...maybe I'll try what you did with mine and see if I get the same result.....

 

[Wyrguy]

C-J, it sounds to me that something really isn't right... Where are you located? PM me if you're around Victoria/Lower island and I'll come and have a look at it.

Wyrguy Rick


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[C-J]

Sounds kind of strange.......I have a Minn-kota...maybe I'll try what you did with mine and see if I get the same result.....

Thanks Seafever...much appreciated!

 

[Seafever]

Hooked up the Minn-kota to a battery......but motor was not in water.

Connected tester '+' to fin on motor and minus lead to minus on battery.

With motor off:- did get a fluctuating reading of up to .04 of one volt when I first hooked it up. But then later that disappeared.

With motor running.......no voltage of any kind. tried the fin and several places on the metal housing that the fin is attached to that had bare metal spots.

 

[C-J]

Hooked up the Minn-kota to a battery......but motor was not in water.

Connected tester '+' to fin on motor and minus lead to minus on battery.

With motor off:- did get a fluctuating reading of up to .04 of one volt when I first hooked it up. But then later that disappeared.

With motor running.......no voltage of any kind. tried the fin and several places on the metal housing that the fin is attached to that had bare metal spots.

Thanks Seafever...that's some more useful data. I took my boat out to the lake last night. When everything was totally dry I wasn't reading any stray voltage. When the boat was in the water I could get a reading of 6.4V off of the metal on the motor and also the rudder when the engine was running. When I put the positive probe in the water beside the boat while running got a reading of 6.0V. Seems off...hopefully can get wyrguy to have a look at it to help diagnose and will report back.