My speedo was bouncing around and inaccurite for quite some time so I figured I would try another speedo and a new cable. Now I have no movement from the needle at any given speed. I would like to make some progress with this thing so let me know how to trouble shoot this.
Very simple, first start off by pulling your speedo gear out, it very well may be stripped to nothing.
Also put a cordless drill on high speed on the end of the cable (pull it out of the sensor) and have someone watch the speedometer. If the cable and speed are good, the speedometer will read something.