tail lamps

I'm having a time with my 79 firebird on the electrical system. I've tried finding others with the same problem as mine but turned up nothing. I lost my dash lights and taillights but my headlights work (all 4 of them) I've replaced the switch and the dash fuse. Am I using a wrong fuse? Is this...

Just had to replace my OER tail lamps after only 4 years as the color faded from sun UV, and I live in the Pacific North West were we don't even get much sun! Has anyone found any kind of UV protector spray I could apply to the tail lamps to have them last a bit longer this time?