[celeste]

I recently purchased a 2000 Mustang. Sometimes it runs fine, other times it won't start and the anti-theft light is on. Once the light came on while I was driving and it shut down the car.

I have taken it to my local Ford service department. They've had it for a week and told me to pick up the car because they don't know what's going on.

Has anyone else had this problem?

[gnr_70]

Try this....remove the cable from negative terminal off of the battery for about 20 minutes. This usually resets the computer of the car and will remove that light form the dashboard.
Is the original stock radio system (Mach 300 i think it is) still in there or is there a new radio installed? If so, this could be one problem. Somewhere in this website I read that if you remove the original stock stereo you will have problems with the anti-theft.