been looking for one, trying to hook up a new speedo and tach from speed hut. wanted to use the stock harness for the wiring.

 

The two pages below from the "Mazda RX-7 1994 Body Electrical Troubleshooting Manual" section C1 should help. The two pages, taken together, show the complete schematic and pinouts of "C1-01," which is actually four connectors to the instrument panel.