Check the fuse for the interior lights or gauge cluster. Also, does your trunk light light up?...what about vanity mirror lights (if you have them)? And what year cougar do you have, I see you have Aussie headlights in your Avatar, but that doesn't tell me much...I'll check on which fuse it is again..
<u>EDIT</u>~After looking at my 2002 manual, you should check fuse number 34 and see if it's blown. This happened in my old 99 when I crossed a wire by accident....this fuse controls the Power Mirrors, Clock, Interior Lamps........if you notice any of those 3 not working, check this fuse.