Since "stopped working" can mean all kinds of different things, you can check the two fuses first but expect to make an expensive trip to the dealer. GM stopped allowing us to buy radio service manuals after the '94 model year so they could have all that repair business for their two grossly over-priced repair centers. If you have a cd player, GM's have a 100 percent failure rate. They won't fix it. They will just install a complete mechanism like the old one.