While you're waiting for somebody who has the same year and model as you do to chime in, I'll suggest one thing:
It seems to me that Fleetwood put an ICC switch in some Bounder models around your era of coach. The ICC switch will temporarily disable the clearance lights but should be a momentary switch. Maybe check to see if that switch might somehow be stuck in the off position? In some Bounders, I've noticed that the ICC switch on the left-side console below the window. If that isn't it, there may be an in-line fuse that is separate from the main fuse that might have blown.
Lots of folks that participate on this forum are wiring and electrical wizards so hopefully somebody that knows more than I do will see your thread.
You might keep in mind for future inquiries that may be more model specific than this one, that this forum has a Fleetwood Products Owner's Forum ...
go HERE.