Anybody know of any faults on an astra g that causes the airbag light to come on?

could be anything TBh, and before you go about fidlling wth the system, please be aware aitbags are explosives, leave the key in and boom, disconnect the battery and leave for at least 30 mins,

id bet on it being the connectors under the seat, maybe disconnect the battery and have a fiddle, disconnect the multiplug and check

Quite common if the battery has been disconnected or alternator or fanbelt playing up.

Ya need tech2 to reset it (or diagnose).

The door locks were playing up so i've fixed them an now an airbag light has come on, I think it could do with a new alternator now you mention it, it has been playing up. Thanks for the help

I had a daft one on my Zafira over the winter when the washers froze up, this blwe the fuse and meant that the boot couldn't be opened... (why are they on the same fuse?)

So with your door locks having an issue it may be worth checking the fuse box under the bonnet.

You could check if there is a corroded earth strap or bad battery connection, best bet would be the alternator - the fault could possibly be that you had a new alternator fitted and the ECU may not have been reset properly.

If you have been inside the door?? the doors contain sensors for your air bag(side impact) If your seats have airbags!. You might as well go strait to a garage as already said, fault code will now need to be removed with tech 2 or laptop with software. I have stood next to a bloke putting the door pad back with ignition turned on, when the bag went off,he only gave it a palm slap.If You do not have seat bags the wires under the seat are for the seat tensioner be very wary static can set them off and it will haveyour hand if its in the wrong place