If this is a stock tachometer and hasn't been upgraded to use electronic ignition, it wont work.
Premium Dash Decals, Mr Heater Box and Classic industries carry the proper circuit board for electronic ignition. Its simple to install.
To test it outside the car you need 3 long test leads with alligator clips on each end. Hook the positive to the + terminal on the tach and the positive on the battery, Negative from the tack housing to battery negative. last lead goes from negative of coil to the terminal with the spade connector. See below.
Hope this helps!!
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