Have a 2006 Sportster with a speedometer needle that pegs out when power is applied. Tried to replace with a new HD speedo/tacho combo. When plugged into the data link port for calibration, per instructions, it just says "no cal". It seems to not be communicating with the ICM. Broke out the wiring diagram and started checking continuity. Pin 4 (gray wire) has zero ohms to ground. I don't believe this is correct, especially since it ties to the red black cable of the ignition.

It appears that pin 4 of the data link is grounded. With that said, there are no issues with the bike starting or any of the lights. Just the factory speedometer needle pegging out when power is applied. Also have a fault code of U1255 and U1097.