My speedometer drops down to 0 while driving?

I think they're probably correct.

Speedometer cable maybe twisted or ready to brake

hi,i have a similar problem on my ford focus 2001...ill be driving along and the speedo will drop to zero and the battery light will come on.Just had a new alternator as last one was overcharging would the speed sensor cause the battery light to come on? if so ill get the sensor replaced but dont want to if this is not the problem

I would test your alternator..when you car isnt charging and battery voltage drops below 9.6 volts your instrument cluster will perform a reset...or shut off..as for the door locks im not entirely sure why they would stop working...good luck

sounds like you will need a speed sensor wich is located on transmission.

Two questions: Is your odometer working? If not then it's probably a broken gear by the stepper motor that Emissionwiz mentioned. Is your ABS and/or TRACS light on intermittently or constantly. If so that is a common sign your ABS control module has gone or is going bad. This usually happens before the speedometer starts acting up. Either one of these will start intermittently and finally end up with the speedometer not functioning at all, and both are pretty common failures with this model.

speed sensor on the transmission.

replace the speed sensor on top of the rear differential housing

I also had the same problem, had to switch back to Motor Craft voltage regulator with the Bill Blass model Mark VII.

your gauge is faulty. yours is operated by a circuit board and and not a cable. it will have to be replaced by a new one.