Speedo Won't calibrate

[dagall]

One wire is grounded to the frame and the other green is attached to the speedo. I pressed and held the button and started the car. Needle went to full scale and when I started the two mile run I pressed the button again to half scale. I saw the pulses appear in the window through the two mile run. Stopped and pressed the button and it appeared to reset. I did this twice with the same result. The needle bounces all over with no speed being able to be read. Do I have a wrong wire hooked up somewhere or? Thinking of just picking up a GPS adapter.

[wallace18]

The pulse wire from the speedo has to go thru the sender and then to ground.

[dagall]

There are two wires labeled from the speedo for sender. Which is the correct one? There are two wires from the sender, one green goes to the speedo and the other is grounded.