Another Tach not working problem

[stevef]

I've finally got my 2.2L rebuild running in my 71, The last thing I have to fix is the tach. I've done a search but can't find a clue. No signal to the tach. The Purple and Black wire is attached to the distributor, runs through the rear electrical panel, through the speed switch and on to the front of the car.
When I connect the purple and black wire to the +ve side of the coil I get a signal so I know the continuity of the circuit is intact but obviously the tach reads something associated with the signals being pulsed from the CDI. Any ideas what I should be doing and why I'm not getting a signal from the distributor when the engine is running?

[Early_S_Man]

Have you ever looked at or printed Pelican's '71 schematic???

Did you bother to check the multiple connection at the Speed Switch or maybe at the output side of the 14-pin connector going to the front of the car???

Considering that the 'signal' you are looking for is a 12 Volt squarewave, not +460 Volt pulses ... it wasn't real bright hooking the tach to terminal 15 [your '+ve' cryptic notation] of the coil ...

There are several places you can send your tach to for repair ...

[stevef]

OOPS!

[stevef]

S man. I'm hoping we've got our wires crossed too. The early S diagram shows the Black and Purple wire coming off the +ve side of the coil (I don't mean the High Tension terminal lead,I mean the other terminal than the -ve or ground wire) The 1971 T diagram shows the Black and purple coming off the dizzy through the speed switch. I tried the +ve coil because I have a Marelli distributor on a 2.2 motor in a car that the PO ran a 2.7 CIS in so I'm trying to piece back a functioning car.