Originally Posted by souzafone

The bulb and socket are one piece, and probably not available aftermarket. They are identified by a number inked on the bulb, e.g. pc194, and the color of the socket. Don't just get one that fits, too much candle power can melt the cluster lens. Go to a large GM dealer and they should have them. If you have difficulty finding one, pretend you're lost and make your way to the parts counter the dealers techs use. Clusters are rebuilt for GM and the parts guys always grab a few bulbs before sending them out.