speedometer & tach failure
 

The speedometer & tachometer on my '93 RX7 ceased to function at the same time. Can someone tell me the probable cause and resolution?

Check fuses

don't quote me on this but I heard the ignitor controlls those functions.

Tachometer is from crank angle sensor.
Speedometer is from vechicle speed sensor.

I would check the routing and connections to your gauge cluster before anything else.

Well, I've had this happen once shortly after I first got mine and a fuse (maybe even two) blew. Just a suggestion from my experience. :D

If fuses are blowing ther is a short somewhere.

True...of course, it never happened again on mine. Go figure. :D

my speedo and odo dont work, before i pull out the speed sensor, any idea which fuses i could check?

They would be under the dash, but I'd go with clayne too and check for shorts too.