tacho connection help

[DaveA]

having just changed my engine from one which had a tacho sender unit , to my new engine which has a tacho sensor on the alternator.
anyone know if I can still use the same tacho from the old engine set up , and if so how do I connect it ?
the connections on the tacho are marked G . W . 12 and - .
thanks.

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[oldharry]

Unlikely. Engine sensed tachos are usually only counting a few pulses per rev, while alt tachos are sensing the a/c waveform, and counting that. However it might be worth contacting the makers of both engine and tacho to see if it can be modified.

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[ean_p]

Don't know what the G is but believe that W is connected to W or ac output pin on alternator and that 12 is battery positive (if 12v) and - is battery negative

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