Τhanks a lot for your replies. To get a signal from the alternator, from which point of the alternator should I get that signal? My alternators look as at the attached photos. Thank you.
A related thread is the following
https://www.dieselplace.com/threads/alternator-wiring.971904/
I own a 1986 k10 6,2 liter diesel engine chevy truck that has no tachometer. Please, could anyone guide me how can i install a free market tachometer on the dashboard and what kind?. Thank you very much.