I'm having a strange problem with my car (2004 Octavia 1.9 TDi) that hopefully someone here can help with.

On Saturday 22 July I found that the electric windows would not work. I stopped the car and opened the fuse box cover and pushed in all the fuses. The windows started working and I left them closed as I didn't want to risk them opening and not closing.

I parked the car up at my parents house and went on holiday for a week.

On Monday 31 July, the car would not start - its battery was flat. I called out the AA and the very nice man said that the ECU that controls the windows had stayed on all week and flattened the battery. He jump started the car and the windows did not work. He disconnected the battery to give everything a master reset and fiddled about with the window switches and the windows started working again. We left the engine running for about 30 minutes.

I then switched off the car for 5 minutes and then took it for a short drive - the windows did not work.

I called the nearest dealer (Kings Heath in Birmingham) who kindly agreed to look at it the same day. On the way to the dealers the windows were working. They were still working when the technician looked at the car and there were no faults logged, so there was nothing they could do.

This morning the windows were working.

This evening the windows are not working.

I'll call the dealers tomorrow to get it looked at.

Thanks for reading all of that. Please post any suggestions for fixing this.

Update: I tried the windows again with just the ignition on (not the engine) and they still did not work. I switched ignition off and removed the key and the pushed in all of the fuses again. Switched ignition on and the windows were working.

Bump!

Fault in the convience unit? Or corroded wiring as the unit is in drivers door.

It's going into the dealers on Monday.

The windows have stopped working altogether now.

I found out that it was fuse number 5 for the windows, but the fuse was fine.

Did you ever find what the problem was ?

My Octavia has started doing exactly the same thing, was it the convenience unit?

Anyone know eher I can get a cheap convenience unit...:(

They just replaced the window motor/control unit in the drivers door last week, the problem has been coming and going since last July. In the past they also replaced the window switches in the door.

Diagnosing the problem was made worse by the fact that disoneecting the battery sometimes fixed the problem so whenever they replaced a part (any part) the windows would work again.

Accordining to the dealers the flat battery was caused by something else and not related to the window fault. They replaced something else for that.

Ok thanks.

Do you know if they have tried replacing the convenience control unit?

(Looks like they are expensive so I guess they'll try the other things first...)

Are you still having trouble with the battery going flat intermittently?

If not do you know what they did to fix it?

(Off to France on holiday soon and I've yet to work out the French for "Any chance of a jump-start?" )

I don't know what the convienience unit is, the dealers have never mentioned one to me so I'm assuming they have not replaced it. Mine is still under warrentee so I don't really bother with the details as I dont have to pay.

I have not had the battery problem again, but I have not left the car for a week again. I think they replaced some sort of fuse for that and they said it was unrelated to the window problem.

Ok thanks.

(Off to France on holiday soon and I've yet to work out the French for "Any chance of a jump-start?" )

Looking Scottish and waving my jump leads about usually works for me! Do you have European cover on any breakdown insurance if you're really bothered?

So in case it is of any use to anyone, on the 4th May I dismantled the console enough to remover the convenience control unit (As described elsewhere on the forum ), opened up the unit, cleaned all the contacts, checked for dodgey joints (couldn't see any.) and doused it and the connecting lead in contact cleaner. Reassembled and haven't had any problems since...

Limited french/kilt & jumplead not called into play

This has been happening to me. I had the regulator replaced on the passenger side but the windows were going nuts just before and are now worse.

I have to use the key in the 'lock' position to close all the windows but that does not guarantee the windows still being closed in the morning. Or the battery being charged enough to start. Kind of a problem without a garage.

I'm thinking it might be something to do with the wiring somewhere..the loom..(is that the convenience unit?)

J.

I think you're on the right lines; the "convenience unit" is an ECU, which runs "convenience functions", such as the leccy windows, central locking, sunroof...