I have an old Chrysler parts 3004195 tach. It has 4 wires, black, white, orange, blue. The blue wire is a little thicker. Where are the wires connected to?
TIA, John
Not sure if this helps as I don’t know that tach:
Most tach from that era need 3 wire to run. Ground, key on power and trigger. Then one for the internal light that connects to the dash lights.
If I had to take an educated guess-
Black or white is ground and key power
Orange is dash light and blue is trigger
Dixco wiring shows black, white, red, and green
I'd bet your orange is their red, and your blue is their green
So, slightly educated guess:
Blue to coil neg
Orange to 12v
Black to grnd
White to instrument lights
I am NOT responsible for wiring errors, this is a GUESS!!