One problem related to air bag on-off switch has been reported for the 2003 Mercury Grand Marquis. The most recently reported issues are listed below. Please also check out the statistics and reliability analysis of the 2003 Mercury Grand Marquis based on all problems reported for the 2003 Grand Marquis.
A spring in the driver's seat belt buckle failed, causing the airbag light on the instrument panel to illuminate and deactivate the air bag system in the event of a front impact requiring air bag deployment. The seat belt and buckle was required to be replaced. The air bag light illuminated every time the driver fastens the seat belt. The airbag light stays on and would not go off when the driver fastens the seat belt. The dealer traced this to a faulty seat belt latch. From reading on owners¿ blogs of this model, over several years including my model year, my problem does not appear to be a unique or rare occurrence. The most common causes are worn or broken springs on the switch in the seat belt latch. The switch in the seat belt latch not recognizing the driver in the driver¿s seat with the seat belt fastened causes the light to go on and deactivate the airbag restraint system for the driver. This safety item should be a model recall.