pertronix wiring 74S
 

I have bought a Pertronix Ignitor to replace my points in my 1974S.Went to wire it in but the instructions dont tell me what to do with the black & grey wires that that are on the the dizzy origionally.The supplied wiring diagram shows the red & black wires from the ignitor going to the coil but no explanation for the 2 existing wires.If anybody has installed or has a wiring diagramfor this i would really appreciate any help.

bede,
The original wires, black and grey, one goes to terminal C of the CDI box. The other wire goes to the tach.
When I connected up the Pertronix I ran a red wire with a female connector from one of the switched 12 volt fuses, and a male connector on the red wire from the pertronix.
I put a male connector on the black wire from the pertronix, and a female connector onto the existing wire that goes to terminal C of the CDI.
The connectors are for a disconnect when I remove the distributor.
So basically all you need to determine is which of the black and grey wires goes to the terminal C of the CDI box. The other wire goes to the tach.
I'd connect up the tach wire after I got things running with the Pertronix.
You have a choice of where to tap into the wire from the distributor to terminal C of the CDI box. Which ever end is convenient and neat.
I hope this is the info you were looking for.
Please post your results.

Thanks That is starting to make some sense.I will run the red wire from the pertronix to a switched wier at the fuse terminal near the cdi unit& i will join the other black wire to the wire at the dizzy that goes back to terminal C at the CDI.Then the tacho wire must join on the terminal C wire as well.Sounds good Cheers

Did exactly that hooked up the tacho wire as well & it worked perfectly.Had to re do the ignition timing it was out about 5 deg it is now running sweet Thanks for your help