New Tach hookup - wiring help please

[shawski]

Hi all,

I'm putting in a nice new tach on my nice new uncut '68. I'm looking for the cleanest, most appropriate two wires to tap into. I have a stock harness.

1. Need to tap into a 12v power. Which wire under the dash would be best for this?
2. Need to tap into a light source. Would I pick one of the wires on the back of the "lights" knob on the dash? If so, know which one? If not, better recommendation?

Thank you guys!

Shaw

 

[Viperwolf1]

For 12V power add a wire to the stud terminal on the back of the ignition switch. Any blue-red stripe wire should be cluster illumination and the brightness will be controlled by the light knob.

You'll also need a good ground and a wire to the neg side of the coil.

 

[shawski]

Awesome Viper,
Thank you. That "stud" terminal you're referring to, is that only one on the back?

thanks

 

[Viperwolf1]

Yep. It's 12V only in RUN and ACC.

 

[Stroppe-Envy-77]

Assuming you're mounting it on the steering column, here are a couple more ways to keep it nice and clean:

1. If you're using the "traditional" hose clamp mount, slide some black heat shrink tubing over the parts of the band that'll be seen. (Shrink it down with a heat gun, of course.)

2. Do the same with the wires coming out of the tach. Heat shrink tubing, especially in black, keeps it low-key and almost factory looking.

3. Use a rubber grommet for the hole in the plasic column surround (assuming that's where you're passing the wires through). The wrapped wire bundle should have just a slight amount of slack to it.