Weird airbag light fault

[serenmor]

My van is a 2004 Mk 6, petrol/LPG, 2.3 ltr DOHC engine.
I have a problem with the airbag light permanently on, although a scanner shows no fault or fault codes.
What happened was this: (please excuse the following lengthy explanation):

I took out the instrument cluster to clean the circuit board, as a few digits were not showing on the trip recorder. When I took the cowl off the ignition I noticed a key taped to the ignition barrel, which I took off thinking it was a spare. After that I couldn't start the engine and I got a fault code on the immobiliser saying "key not recognised". Thanks to advice given on here, I put back the key on the barrel and the engine started ok,I didn't know the key had a chip which the immobiliser had to read.

So far so good - the engine ran and the trip recorder was fixed. The problem then was that the airbag light will not go out. I checked the wiring and it seemed ok. I went to a local garage and they could see no fault with their scanner and were mystified.

The other weird thing was that the beeper which sounds when you open the door with the headlights on suddenly started working again, after being non-functioning for maybe two years.

As far as the airbag goes, the mechanic suggested I simply discoonect the warning light at the circuit board, but I am reluctant to do this if a proper explanation can be found.

Any ideas, anyone?

[Altransit]

As far as the airbag goes, the mechanic suggested I simply disconnect the warning light at the circuit board, but I am reluctant to do this if a proper explanation can be found.

Best not to do that, it will fail the MOT if the light is either on all the time, or off all the time. The tester will expect it to light up with ignition and then go out to confirm the system is working. Does it not flash a code before going solid, when you switch on

[Nordic Blue]

If you're saying the airbag light wasn't on before you took the cluster out, my first thought would be a bad connection on the cluster plug socket. You said various other things didn't/did work, so I think the first thing would be to have the socket resoldered on the circuit board.

If you're methodical and handy with a soldering iron you can do it yourself, or there are companies that fully refurb these clusters for a reasonable charge. Or, I suppose you could get a second hand cluster but risk more of the same issues.

I would have thought making sure the board is right first might be the best first step.

I had issues with the speedo and rev counter regularly going off and the mileometer changing to dashed lines. I resoldered mine myself but it took a couple of goes - I noticed that the plug and clip are a powerful force - each time I plugged the board in the van to test it caused more cracks in the thinnest solder joints on the socket.