Tacho install, old van

[jospanner]

Hi,
I am trying to install a tachometer/rev counter into a 1981 air cooled.
My alternator doesn't seem to have a "w" terminal, and as it's an older van it probably doesn't have the existing wiring?
I see a 3 pin plug, marked D and B at either side, and one spare terminal that is unconnected, guessing that's for a suppression cap.
What should I do? I was told by someone else that tapping into the coil green wire is a bad idea..

[jospanner]

Here a pic...
https://u.pcloud.link/publink/show?code ... VGmznpgaKy

[AngeloEvs]

Yours is petrol so forget about using the Alternator which drive Tachos specifically designed to be used with diesel engines, they are calibrated differently and require a different type of pulse.

You will need to use the coil and tap into the Green wire, there is no problem doing that if you do it correctly, LPG converted vans and many others tap into the green Coil cable for a variety of reasons.   You will need to run a cable from the engine bay to dash and, at the dash, add a 12v supply (Ignition ) side, tap into the panel light feed and add an earth connection.  If you do not want to tap into the panel light feed then connect your  tacho panel light connection to the Tacho 12v supply - the tacho light will be on when the engine is started but since most use LED backlighting it doesnt matter that much and simplifies installation.

[jospanner]

Nice one, yeah I'll tap into the green wire then! Thanks!