Chrysler Repair: Broken odometer/speedometer:97 Neon, plymouth neon, cv joint

Question
I hava a 1997 Plymouth Neon and the odometer and the speedometer randomly quit working.  It is not a digital screen and I am worried the the miles are correctly being calculated.  What could be causing this?

Answer
Hi Lisa,
There is a mechanical sensor mounted on the transaxle housing under hood which is electrically connected to the engine control computer and to instrument panel speed/odo.
It might be that the plug-in at the sensor is loose or the wires are damaged, but also the gear on the sensor itself could be worn out/damaged. I believe that if you have had the cv joint on the right side half-shaft replaced or the entire half-shaft replaced that the gear on the sensor may have been damaged in that repair job. The sensor is supposed to be removed before you pull the half-shaft out of the housing.  
If you look behind the engine and down at the level of half-shafts you will see the housing into which the half shafts are inserted. On the top side of that housing the sensor is positioned, held in place by a single bolt and with a three-wire plug. You can remove the bolt and lift out the sensor (maybe requiring a thin screwdriver or blade to pry it up and out of the housing at its edge). Then you can inspect the gear for damage. Also, check the wires and that the plug is inserted into the sensor even before removing the bolt for the sensor.
That is probably why you are loosing the speedo/odo function.
Roland