do you have the cover off the connections on the motor? look for obvious damage or rust / corrosion at the jack terminals, note which wire are connected where on the terminal strip. If the connections are ok then I would suspect the cable is damaged between the receiver and the jack, or the sensor itself has given out. If it is a 14 year old reed switch in the sensor - - - the chances of it failing are over 80%. If it is optical, 14 years of dust and insect collecting may be a problem.
Hope that gives more ideas / insight - at least for someone who has done BUD work since I have.
POP