One problem related to ignition switch has been reported for the 1999 Ford F-250. The most recently reported issues are listed below.
First day-accessories stay on while ignition switch is turned off & key is removed. Second day-batteries goes dead, wipers turn on by themselves, speedometer quits, transmission will not shift, 2 different buzzing noise from under dash, dome lights flashing on & off, abs brake lights come on. We have had no recent mechanical work done. No single source causes all these problems at one time.