I am trying to use a auto meter 3 3/4 tach on my project car. i hooked up the sending wire to the yellow tach output wire on my trailing coil pack. with the haltech installed, is this still the proper way to get a tach reading? It is reading now, but bounces rapidly between 500 rpm and 1000 rpm and does not increase with the motor.

 

i have the tacho set up for 2 pulse per revolution

 

bump