Electrical systems having a meltdown!

[Josh]

Hi Guys, I'm very new to this, but hope someone can help. I've enjoyed my 2003 Z4 for the last year with no problems except the central locking on the passenger side not working which I can live with.
In the last 48 hours I've experienced a system meltdown. It started with the roof not opening but everything else worked then about an hour later I parked up and closed the the windows.....no problems other than the roof! 2 hours later started the car again Windows and roof not working and Steering heavy (lost the assist) later on windscreen wipers and squirt failed. Today indicators have failed. Worried what might go next I'm glad i'm not in an aeroplane!! Engine starts and runs OK as normal as does the radio, heated seats, Lights. The windows have power as when I opened the passenger door to check the fuses (It's LH Drive!) it dropped an inch as usual......however has not gone back up when I closed the door. The Drivers window has now crept its self down to half way, leaving the car insecure in a public car park. It seems no fuzes have blown. Does my car need Exorcising by the local priest? My main worry is the windows ........ Can I get them up (shut them) manually somehow so I can at least secure the car ?
Please help someone if you can!

[Marlon]

Could be the battery - has it ever been replaced? If not its 16 years old!

[ph001]

Battery is first thing to replace as Marlon suggests. If that doesn't help it's likely to be canbus corruption and the no.1 culprit for that is the airbag control module. Any moisture in there tends to corrode the connector and cause the canbus problems.

If you pull the coin holder out in the centre console in between and just behind the seats you may be able to pull the connector off to check if everything returns back to normal (the downside being the airbag light will come on, but at least you can secure the car!).

[Josh]

Thanks guys for replying so quickly. I shall have a look and let you know. Actually the 'air bag' light came on this morning anyway.

[ph001]

...then almost certainly the airbag control module