RX-3 tach wiring
 

Anyone fairly familiar with the dash wiring on a '73 RX-3 coupe? Basically, I am trying to get the stock tachmometer working. I believe the previous owner had an aftermarket tach wired up, so I'm not sure what they did in regards to the wiring. At first I suspected the tach itself was bad, but I have recently tried a 2nd gauge cluster and it does the same thing: nothing.

Which coil does the tach get its signal from? From what I can tell much of the underhood wiring was redone by the previous owner, but I just want to get the stock tach working for now. If anyone knows offhand the wire color for the tach signal that would be great. I looked at the online schematic but it doesn't appear to be on there.

Thanks,
Mike

this is from a 73 wiring diagram, its the yellow/green wire from the negative side of the coil.

Any body else need a diagram let me know.