Ghost in the machine...

[willd]

If anyone can help, I'd appreciate ANY theories on this. Even really vague ones!

I drive along, windows and roof are up - without warning the windows will drop, all the way down. At the same time the windows drop down, the courtesy light comes on as if the door has been opened. I use the window switches to do them back up, and when they're all the way up, the courtesy light goes off again. WTF???

Why would the windows going down activate the courtesy light?

The centre console microswitch assembly - I replaced that already, but in theory that would only cause the windows to drop a couple of inches before the roof comes down - not all the way.

I thought maybe an inertia switch, that drops the windows and puts the light on in the event of an accident....but surely that would cut the engine too?

I stripped the door down today to see if there was anything obvious with the door handle/lock mechanism. It works fine, and I couldn't see anything obviously wrong. I check this on the basis of maybe the facility that when you turn your key all the way to the right/left for XX seconds it's meant to do the windows up or down. Although mine doesn't seem to work.......

:ah:

[eightsandaces]

Is there anywhere you could get an OBDII read just to see if it threw a code? I'll volunteer to look it up in the Bentley book for you if you retrieve one.

[willd]

Thanks, that's really kind of you, but unfortunately I have an ODBII scanner (the generic type), and there were no fault codes stored.

It's almost like, whatever is happening is happening as part of a normal car function....if you see what I mean?

Just trying to pinpoint what 'normal' car functions would cause these symptoms is really hard though...

Thanks anyway!

[extanker]

although its a BMW Z4 [wifes] it has the feature of turn and hold key ....the top does its thing [up or down] the windows go up or down [depending on what you want the system to do] i,ll guess it has a controll module for this function and yours is getting a signal [wrongly] to take this action. does it do it if you go over a bump/turns etc. you could try discoing the door electrics and ride around or find [if app] the controll module and tap on it etc. the beemers inside lights come on when the system is working

[eightsandaces]

To dovetail onto the last post, the connections to all the modules should be checked, might get lucky.

[extanker]

Originally Posted by eightsandaces

To dovetail onto the last post, the connections to all the modules should be checked, might get lucky.

good call i forgot to say that