UK Car Repair: Airbag on 1996 xj12, jaguar xj12, system fault

Question
I have a 1996 jaguar xj12, and the airbag light comes on, as the odometer says airbag instead of the mileage reading.  It takes almost a minute after start-up for this to happen.  The care has sat most of the year.  I checked all of the possible fuses, what can I do next to reset/correct the system

Answer
Just so I understand; when you switch on the ignition does the light come on, then go off after 7-10 secs?  Make sure all of the seat belt catches are locked and nothing heavy is on the seats. The problem is most likely in the control module behind the airbag on the passenger side. These are complicated systems and are best left to a professional.  If you are going to work on the system disconnect the battery for at least 2 minutes before starting. All you can test is that the feeds are intact, disconnect the grey connector from the module there should be 2 feeds, the yellow/white comes from a fuse to the instrument panel the Light green/slate comes from the ignition switch when on.  Clearly you have to connect the battery temporarily when you do these tests, do so AFTER the plug is disconnected, then disconnect the battery again until all is refitted. It is unlikely that the airbags are inoperative, this is more likely a test system fault and so the car is drivable and the light may rectify its self after being driven!