What will make a 95 buick lesabre speedometer jump,car cut off and then

[demonoid_dan]

battery dies just sitting in yard? While going down the road the speedometer will jump like crazy,the car will jerk and then cut off. It will crank right back up sometimes but not always. If i'm lucky to get it back home the battery will be dead the next day just from sitting over night. I've changed the alternator. And now the engine will turn over but it will not fire up and while the key is in the on position it will make a weird constant clicking noise behind the passenger airbag/dash area that sounds kinda like a jackhammer but with a clicking noise and then you can hear a loud hum near where the fuel pump is. I've checked wires and everything and i don't know what else to do b/c it is impossible for me to move to get it to a mechanic.

 

[Unregistered]

I had the same problem with the speedometer on a 97 buick lesabre jumping around, and exceeding the speed.

After replacing the crank position sensor, ignition coils, and wires The speedometer is back to normal, and it runs perfectly.

See if you can get the error codes for your buick (assuming the check enigine light is on). This may narrow down the sensor.

For the speedometer the other sensors to suspect are the cam position sensor, vehicle speed sensor, the ignition module, or the pwm.