Tachometer has stopped working Safari Sahara Diesel

So, tell us what terminals the alternator has OR its model number.

All will have: B+ for positive alternator output to battery or battery isolator.

Ground-- some ground through metal to metal contact, some have a separate ground lug and wire.

Some will have a "sense wire" from chassis battery side of the battery isolator to the alternator sense terminal (small gauge wire).

Some will have an excitor wire which is hot only when ignition is on.

Some will have a tach out terminal.