Rewiring the engine and Starter Battery Current Leak

Eric Freedman

If we are talking about a yanmar there is heavy black wire that runs from the solenoid that grounds the block grounding. It runs  all around the back of the engine to the alternator. It is jammed under the Turbo and is extremely hard to remove.

There are at least 8 sensors and other connections SOLDERED into that wire and covered with electrical tape. Any one of these connections  or the wire itself, if it is chafed, and touches the block will ground the engine.

Here is the photo of the black wire at the engine grounding solenoid.  There are also 2 diodes in the circuit that can short out the system and create all kinds of havoc..



Here is a photo of one of the Amel factory solder joints.


I have had strange electrical problems with the engine over the years.. I finally gave up and rewired the block correctly.

I opened every harness and replaced every wire with “ home Runs” to the grounding system instead of daisy chaining the ground wires. I also ran the new harnesses that I made near the top of the engine for easy access. Each of the harnesses are different colors so I know that the Dc positive wires to the senders , solenoids etc. are in a red harness. The yellow harness has all the grounding wires, and the third harness the green one is for the misc. devices mostly the starter circuit..


Good luck , it only took me a week to rewire the engine.

Fair Winds


Kimberlite Amel Super Maramu #376




From: amelyachtowners@... [mailto:amelyachtowners@...]
Sent: Thursday, March 30, 2017 11:39 PM
To: amelyachtowners@...
Subject: [Amel Yacht Owners] Re: Starter Battery Current Leak



I see Bill's comment about dirt accumulation providing a path to ground. 

I agree, we had that problem on the Yanmar starter motor...not your problem, but salt infused dirt around the positive terminal of the starter solenoid shorted out the start battery when the key was turned...the panel voltmeter went to zero volts!...the motor wouldn't turn over obviously.

Cleaning all around the terminals cured the problem....which was probably caused by the fact that the raw water pump faces towards the starter motor and there's generally quite a bit of salt water around when the cover plate is removed.

Given that the starter battery is only connected to the alternator and starter on each engine as well as the panel switches...they are the places to look...but my bet would be the alternators and / or starter motors and solenoids.

Good luck



Elyse SM437   


Join to automatically receive all group messages.