built91Z28

First off, nothing I have is stock to a 3rd gen. I have a 5" Autometer electric programable speedometer. My trans is a 03 Cobra T56 with the factory sending unit. My speedometer doesnt do anything till what feels like about 50 mph or so. I tried reprograming it tonight and it didnt work. For those who have never used one of these, while programing it, you will see the number of pulses the speedometer is reading. The guage reads 0 till I get up to speed. Then it will start reading pulses. Anyone have anything like this happen? The guage worked when I had my TH350 in with the autometer sending unit for mechanical speedometer tailshafts.