Tach Wiring

[Russell68]

Hey guys.

I have a 1968 f 250 390 engine I am installing a new tach I'm having trouble with finding the right wire for the 12v ignition I found a wiring diagram on this web site but I am un sure which is the correct wire. I think it is the yellow, or the green and yellow. I have no type of testing equipment to confirm which is correct.

So if anyone could help with this it would be greatly appreciate.

Thanks,

Russell

[1972hiboy]

I would just come off the fuse block on a key on ignition source....