One problem related to air bag light on has been reported for the 1999 GMC C1500. The most recently reported issues are listed below.
Airbag light is on. Needs new module and the part is "currently unavailable" from GMC. Repair shop will not guarantee work on installation of a third party part. I have spoken extensively with GMC corporate and they continue to delegate this issue to the dealership level. Imo, the dealership (thorson motor center, pasadena, CA) has done all they can by ordering the part for me. If the part is unavailable, that is not the dealership's fault. Further, there is no estimated time of arrival even though the order has been expedited. GMC corporate should make sure they have sufficient manufacturers who can produce parts in a timely manner. In the meantime, my car has a safety issue that is unresolved. This problem has been going on for over six weeks now.