i am 16 years old and i am trying to install my first tach in my car... i know what the green,red,and black wires are, i just dont know where the white wire goes. If you can help me out, please answer my question... Thanks very much.

 

What Tach is it? Aftermarket? if so what make/model?

 

its a phantom monster tach

 

Random guess: illumination perhaps?

 

Yeah it connects to your Dash Lighting wire so when u turn on the lights the tach also iluminates

The online PDF manual can be found here:
http://hp.autometer.com/instru...n.pdf

 

In my 97 dx, i ran the white wire to the dimmer switch and spliced it to the red/black wire. Now it dims with the other dash lights