I have a 96 camry 2.2 auto and the speedometer bounces all over. Usually it only happens in neutral but recently it started bouncing while driving. The last time it jumped to 140 and stayed there. The transmission shifts fine and the tachometer is fine. Speed sensor checks out too. Only thing I have found wrong with the car recently is a fried ground wir from the battery to the transmission. Any ideas on a cure will be greatly appreciated.

 

Discount the speed sensor and determine if the speedo continues to act erratically.