[C320-list] Intermittent Tachometer Operation

[Ian Neale]

Hi, I have the 3YM30 which does use the alternator as a feed. 

And now having heard the answers here, thanks all, I am almost sure the issue only occurs after being fully charged on shore or solar power. 

So I am pretty sure I now have to live with the issue unfortunately. 

Thanks all for your input. 

Cheers, Ian. 

Sent from. my iPhone

> On 3/10/2023, at 2:10 PM, surprise thompson87.com via C320-list <c320-list at lists.catalina320.com> wrote:
> 
> He says that is true for tachometers that sense from the alternator. The Yanmars do not use the alternator but rather have a separate sensor that detects flywheel rotation directly. Should not be affected by charging state. 
> 
>> On Oct 2, 2023, at 10:21 AM, Greg Flanagan via C320-list <c320-list at lists.catalina320.com> wrote:
>> 
>> If you check
>> Boatowners Mechanical and Electrical Manual by Nigel Calder
>> He says the tach issue is due to high charging rate, yes when you have the alternator and solar it happens. I have the same issue. There isn’t much you can do about it other than increase your house demands (turn on the radar?).
>> 
>> Greg
>> Hoop Dancer #1076
>> Sidney, BC
>> 
>>>> On Oct 1, 2023, at 10:38 PM, Albert Kitten via C320-list <c320-list at lists.catalina320.com> wrote:
>>> 
>>> Have you got solar panels? If batteries are full on,a sunny day? I'll
>>> explain if necessary.
>>> :)
>>> 
>>>> On Mon, 2 Oct 2023, 4:47 am Ian Neale via C320-list, <
>>>> c320-list at lists.catalina320.com> wrote:
>>>> 
>>>> Hi,
>>>> 
>>>> I have an 07 320 with a Yanmar 3YM30 engine.
>>>> 
>>>> The tachometer is intermittent in operation where at times the needle goes
>>>> back to zero while the engine is running.
>>>> 
>>>> I think the tachometer runs off the alternator, but not sure. Wiggling
>>>> wires on the back of the alternator doesn’t seem to fix the problem.
>>>> 
>>>> I have also cleaned all connections in the back of the tachometer.
>>>> 
>>>> Any suggestions as to what could be the problem.
>>>> 
>>>> Thanks, Ian Neale.
>>>> 
>>>> Solutions.
>>>> 
>>>> Sent from. my iPhone
>>>>