[joe_db]

Originally Posted by bigoledave

Great.....

Thank you. I bought my Indigo at least ten years ago. I
conclude it is the "old" design circuiotry.

So...I think I have four.....or more wiring choices.

1) Physically splice in to the "photo interrupter" SENSE wire in the Indigo
harness and connect that to the desired "W" input on the tach,

2) Same as above....yet put that sense wire thru a 5k 1/2 watt resistor.

3) None of the above.....just connect the coil negative terminal directly
to the "sense input" wire on the tach.

4) Same as #3...but splice in a 5k 1/2 watt resistor in the wire
going from the tach to the negative coil terminal.

Opinions welcomed of course!!

Thanks

I would pick #4.