i just got a tach at an auction today and i just realized it doesnt have a knob to adjust between 4-6-8 cylinders, should it still work? its got four wires, two for the light and two others, one red and one green, where do these go?
also got a three hole gauge panel, with an oil pressure gauge, engine temp gauge, and a ammeter, i can figure out the first two, but where do i wire the ammeter to? thanks guys!
if it makes any difference, its a 67 dart gt supersixed 225

What brand tach is it? Some tachs have switches for 4-6- 8 cyl. Some have different color wires to cut or not cut for 4-6-8 cyl. If you go to someplace like Summit Racing and look up your particular tach you may find instalation instruction at the bottm of the page - usually in PDF format. You may also find the necessary info on the other gauges .

Thanks Jeff

thanks, ill give it a shot!

Remove the light bulb and there maybe some switches or wires behind it.

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