Tach not reading

I have a '90 GS. The tach has never worked. I'm not too familiar w/ mitsubishi stuff, I'm used to working on my old chevy. I know that the tach usually hooks up to the coil, but I can't find it on this car. I followed the plug wires and they lead to a box, but there are about 8-9 wires coming out, none look like usual coil wires an are fairly small. Does anyone know how I can fix this? It is really bugging the crap out of me. Thanks for any input.
-Luke :banghead:

http://www.vfaq.com/mods/wiring-gen1wir.html

White maybe?

Thanks for the help, can't hurt to check it out. I'll let you know. Thanks again!
-Luke

Thanks