This morning my speedo was jumping all over the place. I believe I was in neutral, but might have been in reverse and not moving. Needle was all over the place. When I took off it continued and was never reading what I was actually dong speed wise. It even jumped up to 100 a couple of times. Would this be the sending unit on the tranny?

 

What are you driving??

 

96 b2500.

 

Yours gets its clue from the VSS in tailhousing on the trans. Should be a three wire connector. Think I would take a look there first. Maybe an intermittent short in the wiring??