Ford: 1999 F150 O/D Light, ford f150, d light

Question
The Odometer light on my 1999 Ford F150 is sometimes on and then, without warning, it goes off.  Then, after a while, sometimes a long time, it comes back on.  Do you have any idea what might be causing this?  The mileage appears accurate, but it's a pain to not be able to count on it being on.

Thanks!

Answer
BRETT

its probally a bad sensor. i would go to advane auto or autozone and have them put a scan tool on it for free.ford has had some problems with this.if you try to mess with it by taking it apart a tampering warning will come across,and you will have a hard time getting it inspected,or if you sell it you will have a hard time.the dmv had this put in all new cars since 1990 i believe.hope this helps.

ken