Mike, I've had dwell meters with three leads, and others with two. I suspect the reason is a tachometer function as well as dwell readings. It's been a while so had to think on this one.

As has been said already, a two wire setup hooks as described. My 3 wire caught both sides of the coil plus a ground.

I have to admit I've never tried adjusting dwell by just cranking the engine over. On rare occasions I've slightly elongated the adjustment slot with a rat tail file to obtain more travel. In any case I've always made the readings with the engine running. I'd be interested in other opinions on this.


Lead, follow or get the hell out of the way