Does anyone know how to wire this old tachometer. I found it in my grandfathers garage and want to put it back in the car. It has some weird wire colours. They are a blue green and red. Any info on this would be greatly appreciated. I posted pics of the wires and where they go on the board.
Traditionally, The green is a ground <<EDIT - SEE THE NEXT POST BELOW - THIS MAY BE INCORRECT>> The red wire is hot (probably +12 Volts) Which leaves the blue wire to go to the "-" terminal of the ignition coil (also where the points wire from the distributor connects). The circuitry includes 2 resistors,2 capacitors, a diode, a transistor and 2 potentiometers (to calibrate the tach settings). It looks like it was made in the late 1960's or very early 1970's (before printed circuit boards). The quality appears to be "discount store". And that is my best guess. Russ
Drag Fast Tach....maybe a search is in order? https://www.jalopyjournal.com/forum/threads/drag-fast-tach-wiring.703343/ (btw Russ, green is usually the ignition signal wire on tachs.)
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