O/D OFF light appears on dash
My father-in-law has a 1999 Mercury Sable LS 24V DOHC. The O/D OFF light turns on sporadically. When this happens, the speedo does not register, he experiences rough shifting, and shifting is occurring at approximately 3000-4000 rpm's. In looking at my Hayne's manual, it suggests that the VSS sensor might be the cause of this problem. Does anybody have any comments regarding this problem?
I called the parts department at the dealership to see of they had the part in stock and they told me that there are 3 vehicle speed sensors: $30, $60, & $90. Which one should I buy? I thought that he has automatic overdrive to begin with, so why would the O/D OFF light come on, even at slow speeds?
Thanks in Advance,