20R Tach help
 

Hi guys, I'm Ian, and yes, I'm a n00b here, but give me a helping hand if you wouldn't mind. You guys are my last resort!

I recently bought a '79 Corona wagon (20R/5 Speed) as a fun little beater to drive around, but it kinda irks me that the car doesn't have a tach. So I scooped up an Autometer Autogage unit from a buddy of mine and mounted it up just as I know how to (Red to switched 12V, white to lights, black to the engine ground, green to the neg. side of the coil). Well, click the key, tach powers up to set the shift light, start the car, and the tach stays at the RPM indicated for the shift pointer. What gives? Autometer's website says it's becuase the tach is not receiiving proper signal, reccomends a weird hookup for Toyota trucks (i was told because of the ignitor box on the coil?), and I'm guessing it's probably the same for the Corona. :dunno:

All help is appreciated guys!!!!

-Ian