TAMD 63 Alternator charging light and alarm coming on intermittently

[Alistar3000]

I've got a Volvo Penta TAMD installed in my boat. The alternator charging light and alarm comes on intermittently when over planing speed.

Had a new alternator and belt fitted last year. Alternator is testing fine with a voltmeter and alternator/battery tester. Batteries all test okay.

The alarm is coming coming on when the batteries are fully charged. It'll come on for a second or two, up to 30 seconds, before going off. It'll stay off for a few seconds up to a few minutes. So no pattern to it. It seems to not happen below planing speed.

Had the belt adjusted by a mechanic recently and it seemed to be okay for about 30 minutes of running, then the alarm started going off again.

Also have solar panels running through a controller that is on all the time, and a voltage sensitive relay to make sure the start battery gets fully charged first.

Anyone have any ideas on possible causes for the alarm? The mechanic is a bit stumped by it.

 

[makomark]

may wanna try with the solar panel output disconnected....some charging systems don''t like another source connected to their output...

If that doesn't resolve the alarm, I'd check the interconnects between the alternator and the alarm monitor...especially the ground connections...

 

[Trevorleach]

Disconnect solar, do not use shore power for a while and see how you get on.

 

[Alistar3000]

Thanks for the advice - managed to get out for almost an hour running at cruising speed with the solar connection off, and didn't get the alarm coming on, so I think that was the issue.