Re: Onan does not start




On my A54 I had Onan starting problems April 2019 in VANUATU. Almost like it was on a dying battery; when running the main for a couple of minutes the Onan would start. After several days that didn’t work either. The French marine electrician in PORT VILA diagnosed the negative solenoid being the problem. No solenoid available in VANUATU but he happened to go that weekend to NOUMEA NEW CALEDONIA; he hard wired the negative while he got the new solenoid. He did mention that he didn’t understand why the Onan had a negative solenoid anyhow; I was adamant to keep the system the way it was since AMEL has a special bonding system: he also checked with an electrician friend in FRANCE who was very familiar with AMEL boats. Installed new negative solenoid and all was well until 4 months later it went out again when I came back from THE BANKS. Luckily this happened to be in PORT VILA so I was able to use the same electrician. He removed the negative solenoid completely – hard wired and since no more problems.


So the problem for me was the negative solenoid at the back of the Onan.


BTW – all batteries as well as connections were checked (house and engine) and were in perfect condition. Old negative solenoid was corroded though as my SPECTRA NEWPORT II pre-filters are right in that area and hard to change w/o spilling raw water. Even extensive flushing with fresh apparently doesn’t help – unless the corrosion already set in before I got the boat.


Best Regards Teun

SV AMELIT  A54  #128



June 3, 2020 08:35:16


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From: <> On Behalf Of Paul Osterberg via
Sent: Wednesday, June 3, 2020 03:19
Subject: [AmelYachtOwners] Onan does not start


My Onan is totally dead nothing happened when trying to star not a slightest click. I have measured 12,8 volt between +on the starter and minus on the alternator, but only about 4 volt between + on the starter an - I believe it is on the starter see attached photo the same reading 4 v between plus on the starter and the ground strap.
I assume the reading should be 12,8 and not 4 volt?
Any idea where to start searching?
Paul on SY Kerpa SM 259, Lagos, Portugal 

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