Cadillac Repair Questions? Ask a Mechanic for Answers ASAP
If you pull the bulb slightly out of the connector so that it's only just barely plugged in will it work?
I see the connector (pigtail) go bad on these bulbs all the time from the heat they generate. If you can get it to work by either just barely plugging it in or wiggling the connector around then you may have to cut the connector off and wire in a new one.