I have a 1998 mustang and the instrument panel illumination light as well as the other gauge lights, like the A/C switch, rear window defogger switch illumination inoperative. The #13 fuse and all other fuses are good. I have power to the headlight dimmer switch which decreases while you turn it. It seems to be somewhere from the headlight switch and the ins. panel. Any one have this problem before and can guide me to the solution?