Stock Tachometer and sensor install in 65 Dodge Coronet Bench Test

[norseman]

I am installing a stock Tachometer and the sensor in the console of my 65 Dodge Coronet. Is there a procedure for bench testing this before install? I have already tried connecting it to the negative side of the coil and grounding it and not having any luck. I tried bypassing the sensor and the tach goes from zero to full range.