i will be drivin along, and all of a sudden, my speedometer goes nuts! it barries itself then goes to zero and it just goes all over the place.even when the car is off, but i have the key turned to the ignition.i cant figure it out.please help if you have any ideas,will be much appreciated.thanks

 

check the speed sensor

 

check the connector on the speed sensor its probably dirty take the sensor ou cleaned and u good to go thats **** is a common problem

Prego

 

I had the same problem!