My car will die,while idling. The speedometer will go from 0 to 30 or 50
m.p.h.while idling. While driving with cruise control on,the cruise control will
will cut off,and the thieft light comes on briefly. All mentioned,happens ,at
diffrent times. Some days it might happen one time,on any of the mentioned
problems.Any help would be appreciated. Thank You

2003 Ford Taurus
ses
ten yrs. old
100000 miles

 

No quick answer here. You might have one problem causing all symptoms or you may have a number of problems. I would first check for loose electrical connections in particular around the ignition lock (does it feel worn out?) and in the engine compartment. Make sure all ground connections are good. Make sure the wheel sensors are good and clean. Loose wheel bearings could cause bad readings.
There is also a vehicle speed sensor. I believe it is on the transmission somewhere.

I don't know it this will hit it but it gives you a place to start.