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Tachometer connection

PostPosted: Thu Jul 22, 2010 7:24 am
by pmgirling
I have a model 4023-1.
Terminal R is connected to the 'send' of my Tach, but the tach is not responding.
I have 12V at the Tach with Ignition 'on'.
What signal should I see at the alternator R terminal if I use a digital voltmeter?
( It used to work intermittently)

Re: Tachometer connection

PostPosted: Thu Jul 22, 2010 10:50 pm
by Coulomb
You should measure about 1/2 of the output voltage.

If your meter measures frequency, then you can measure that.

Re: Tachometer connection

PostPosted: Wed Aug 04, 2010 11:20 am
by pmgirling
Does that imply that the alternator provides 12 V pulses whose period varies with alternator speed?
My meter is digital: would an analog meter be more appropriate?

Re: Tachometer connection

PostPosted: Wed Aug 04, 2010 12:33 pm
by Coulomb
The tach output is sort of a sine wave with frequency proportional to alternator RPM.

Re: Tachometer connection

PostPosted: Tue Mar 27, 2012 12:35 pm
by pmgirling
Nothing wrong with the tach. Regulator had failed, so no field current, so no Tach output.

Re: Tachometer connection

PostPosted: Tue Mar 27, 2012 12:36 pm
by pmgirling
This new regulator has a connection wire labeled "Stator", with a second
> terminal for "instrumentation" like my Tach.
> Currently my Tach is connected to the "R" terminal of the alternator.
> Is there any risk in connecting the "stator" wire to the alternator "R",
> and relocating my Tach to the "Instrumentation" outlet on the regulator.
> According to my meter, Stator in to Instrument out is a dead short.

Re: Tachometer connection

PostPosted: Tue Mar 27, 2012 5:13 pm
by Coulomb
You should ask that question to the manufacturer of the new regulator.