This is a common problem with 1999 f-150. The problem was worse when the truck was cold and would usually go away as the truck warmed up. The odometer going off and on is caused by a cracked solder joint on the instrument panel circuit board.
If you have access to a soldering iron then you can fix it yourself and it won't cost you a dime. (Well maybe a dime to pay for the solder used.)
Tuesday, November 13th, 2007 AT 9:53 PM