I'm a student at the university nevada las vegas with a '96 dakota 5.2L 4WD. Recently had some weird speedometer problems, when i start driving in the morning, the speedometer works for a couple blocks, than starts bouncing and by the time i've gone a mile it's reading zero. after it has spent the entire day in the parking lot at school, it will work fine for the entire drive home. I originaly thought it was the vehicle speed sensor, so i replaced it, but it didn't help. Any help with this problem would be greatly appreciated.

 

There is a ground wire that can also lose continuity, or it could be a mechanical failure

 

do you happen to know where the ground wire is, because i can't find anything in the repair manual that shows it.