Speedometer not working

95 RMW, Speedometer stopped working suddenly. Code 97 (VSS output circuit) shows up. Here is what is strange: The car still shifts fine and the torque convertor locks at the proper speed. I would think the car would not be able to shift properly and the TCC wouldn't be able to lock without the VSS. When I put the HVAC is in diagnostic mode it appears the correct speed is shown on the HVAC display. I thought it might be the cluster so I put in another known good cluster and the same thing...speedo sits on zero. Temp and gas gauge are working fine. I just took the car up the drugstore, speedo was working fine, cruise was able to set. On my way back, speedo on zero, the slowly rises up to speed but I was already going a constant 35mph. Cruise wouldn't engage. Any help is appreciated.