Rev counter not working with new alternator.

[Jolly Roger]

I have just fitted a new alternator to my Perkins 4-236 motor. It only has a single wire to the battery and works fine. The trouble is there is nowhere to hook up the tachometer. The old alternator had an external regulator and I think a wire went from that, to the tack.
Could anyone advise how I can now get the tack to work?

[capt jgw]

A local alternator shop can install an AC tap to drive your tach. I had that done a few years ago, cost $20.