It could be the underdrive pulley, but somehow I doubt it, especially if it comes on later. What I'm thinking is a loose or bad connection or maybe the console switches are starting to go bad as well. I have a similar problem with my dash lights. Sometimes they work, sometimes they don't. When they don't, a few good slams on the top of the dash usually get the back up and working. I'm at school right now, but I'll check my Helm's manual when I get home and see if there is anything in there. I'd highly recommend you get one for yourself too, they're worth every penny. Seeya.