Trying to find out why my instrument gauge lights weren't working, I fiddled around in the dash looking for unplugged wires and such and thought 'hmm maybe it's as simple as a blown fuse' sure enough, I replaced the gauge fuse and it lit up.. As well as my parking brake light. When I actually engage my parking brake, the light just illuminates brighter then becomes a dull glow again when I disengage. Brakes seem to have no apparent problem or leaks. What could cause this?

 

1989 Astro~~ sorry and thank you.