Bradshaw - based on your second message you may be on to something.
When you mention all of the light functions that are affected, it sounds like it could be in the switch. I say that because there are separate fuses for at least 2 if not 3 of the lights that you mention so to have multiple similar issues is less likely the case.
I would begin to trouble shoot with a tester to the fuse panel at each light fuse plug. Pull the fuse and make sure you have juice coming in. Then you can begin to move forward in the process. Next, I would go to the switch assembly and test each function of the switch, then you can go beyond there.
I think you will find it shortly. Electrical is one of the hardest problems to solve, especially if it is inconsistent.
Good luck, let us know what you find and how you solved it.