speedometer problems on 1999 Ford F-250 Super Duty

my f250's speedometer recently quit working, it would start and stop for a couple of days. have changed the sensor on the rear differential, still does't work

by in Dunbar, WV on August 04, 2010
1 answer
ANSWER by , August 06, 2010
Really need to scan the data stream and see if the computer is seeing the signal from the rear speed sensor, if so, it may be a dash problem or a Central electrical Computer problem that is not letting the rear speed sensor talk to the Instrument Cluster.