Electric Speedometer Problems!!!

I did the S10 V8 swap and when I bought thr tranny for it I had to get a electric set of guages to match the electric tranny but when I put all the wiring in for the dash and tranny my speedometer doesn't work. My temp, oil, gas and battery guage work, it's just the speedometer that doesn't work so if anyone has any suggestions it would ba great help.