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Next Regulator tach overdrive?

PostPosted: Fri Aug 30, 2013 2:08 pm
by petedd
Same great Next regulator, new engine, new alternator.
Ran great for a few hours and tachometer registered correctly and then next time started up, tach ran way high, perhaps 3 or 4 times too high. Any ideas what might cause this and things I should check?
Thanks!

Re: Next Regulator tach overdrive?

PostPosted: Fri Aug 30, 2013 3:43 pm
by Coulomb
The regulator doesn't get involved with the signals from the alternator except when the batteries are taking very little current. Then the signals are generally weak and the tach may drop out.

How much current was the alternator producing when the problem occurred?

Re: Next Regulator tach overdrive?

PostPosted: Fri Aug 30, 2013 4:25 pm
by petedd
Thank you. The only thing I could think of that would have changed the frequency of the winding signal to the tach was if the regulator could be putting out a square or sine wave instead of DC.

To answer your question, likely should have been producing very little current since the batteries would have been well charged by then having just left the dock where the boat was plugged in.

Re: Next Regulator tach overdrive?

PostPosted: Fri Aug 30, 2013 7:49 pm
by Coulomb
Maybe that alternator produces a lot of small pulses when the field current is small, and the tach is sensitive enough to pick them up.