Speedometer problem: 1997 Ford Explorer Sport 4X4. Speedometer drops to zero after a few miles. May or may not come back online right away, but always does after being parked for a while. Checked the speed sensor plastic gear. It looks fine. Checked the Speed sensor with an Ohm Meter. It opens once per rev. Replaced it anyway. No help. From what I can see, the speed sensor gets voltage input and interrupts it once per rev. That signal goes to a solid state unit in the instrument cluster. I would think if the solid state unit were bad it would quit working all together and not drop in and out??? I did have the instrument cluster out to replace some bulbs recently, but the problem started a few weeks later?? Could it be just be a bad connnection at the cluster? Anyone out there have this problem? I hope it in not in the transmission. It is a fresh factory overhaul. One other thing, I noticed transmission fluid was inside the old speed sensor as a few drops leaked out when I turned it downward. There is no seal where the shaft goes in. Only an Oring around the outside. Do I have the transmission over serviced and the fluid gets in and shorts the signal?? I am stumped so far. Any help would be appreciated!
