Where is the fuse for reverse lights on 99 F350?

On a 1999 Ford F-350, the fuse for the reverse lights is located in the fuse panel under the dashboard, near the driver's side. Specifically, you should check the fuse labeled for "Back Up Lights" or similar. Additionally, if the fuse is intact, it could also be worthwhile to inspect the reverse light switch on the transmission, as it can sometimes be the cause of malfunctioning reverse lights. Always refer to the vehicle's owner manual for specific fuse information.