OBS cruise in square
 

After a few years has slipped by I have finally installed the obs cruise in a 77 Blazer and it seems to work only at one speed (56 mph). I have used a 92-96 stepper motor, an Autometer 5291 speedo cruise sensor ( 16 pulse per revolution, square wave ). It’s operates off a single button original style switch.
Hatzie offered advice on the past. I have a 95-02 stepper motor on hand and maybe one or two more. Any comments as to why it works at just one speed?