ixan79

Member
I've replaced the tailgate regulator and it works really well. Just, when I have the engine off and I close the tailgate door, the glass goes down .. (it's getting pretty annoying to have to turn the engine on to up the window after everytime I go in the boot.)

There must be a sensor somewhere that's tricking the system. ..any ideas?


(I assume it's calibrated correctly since it behaves perfectly with the engine on)
TD4 2006 HSE 5door
 
The thing that drives the window down is removal and reconnection of battery. Wonder if there is a loose wire somewhere?



You can raise tailgate window with key in tailgate lock Barrel. Saves running around.



Check tailgate wiring and all plugs are in ok

Did it work before you changed regulator?
 
The thing that drives the window down is removal and reconnection of battery. Wonder if there is a loose wire somewhere?
Its a good suggestion, but its the CCU being 'turned on' that causes this. Not sure how closing the back door only would cause a power loss to the CCU due to loose wire.
 
Is it a 3 door ? Roof off switch command would send window down.

Also, the ccu takes the sensor signal from the hall effect in the rear window motor. If the signal wire gets disrupted then the CCU plays it safe and sends window down command to prevent breakage of glass.
 
Dunno why it only does it with engine off though.

I thought I had seen all possible rear window failures but not this one !!!

So congrats !
 
Very low voltage battery and the latch operating dropping voltage further with no engine running!?!?

But battery wouldn't start car then I guess.
 
thank you all very much for your input.. I appreciate you all
The window actually did the same thing before I changed the regulator. only works with the engine on. (all other windows work fine with the engine off) and i'd had enough of it and in 2018 removed the fuse with the window down enough to close the door.. but the other week i decided to have another go at it and fkd the regulator

I read somewhere that there's a sensor .. something to do with the rear wiper.. but i've tried positioning it every which way. Think I'm just gonna remove the fuse again.

the battery is 1year old but maybe it's not up to scratch? - although the problem existed previously on the old battery, so unlikely to be that....
EuroCarParts:
Lion 096 Car Battery - 3 Year Guarantee
  • Amp Hours: (Ah): 70Ah
  • Cold Cranking Amp: (CCA): 640
 
The thing that drives the window down is removal and reconnection of battery. Wonder if there is a loose wire somewhere?



You can raise tailgate window with key in tailgate lock Barrel. Saves running around.



Check tailgate wiring and all plugs are in ok

Did it work before you changed regulator?
Just went to double check,. it doesn't work at all with the engine off. I can hear the motor clicking when i turn the key in the barrel, but something is stopping it
 
shut the door with window UP? surely that'll break the glass?
I think if the door is open, the CCU will not let the window go fully up, it'll go up as far as where it drops to when you open the door. But don't hold me to that!

Plus, given the strange behavior of your window, all bets are off!

When you say it only works with the engine on, is that with the engine running or just the ignition turned on?

There's obviously a wiring fault somewhere. It sounds like with the ignition/engine off, when you close the door, the CCU goes to wind the window up (normal operation), but the signals/feed gets corrupted and it winds the wrong way - the wrong wire is energised.

I can never get my head around why, but often these sorts of wiring/electrical confusions in the system are caused by poor earths. There is an earth behind the rear 1/4 panel interior trim by the rear door hinges - I presume the window operations would use that. It may be summat to do with that. You could try taking the wires off it, cleaning it and the connectors up and putting it back together.

I believe also that there is a dual relay setup behind that panel for rear window operation. Its a while since I read up on the window operation (when I had problems with mine) but there's a feed for turning the motor 1 way and another for the opposite - energises different wires to the window motor - there may be an issue with these - but I can't think why a problem would only manifest itself with no ignition feed.

Personally, I don't think the problem is with the CCU. I think its more likely to be in the wiring in/around the door. I'm no expert though.
 
Just went to double check,. it doesn't work at all with the engine off.
Has the behavior changed now? Before, with engine/ignition off it would wind the window down when you closed the door, but now nothing?
I can hear the motor clicking when i turn the key in the barrel, but something is stopping it
Maybe its doing the same, trying to raise the window, but the wrong wire on the motor is being energised and its actually lowering the window, but its at its furthest down - hence its 'stalling'.
 
Just went to double check,. it doesn't work at all with the engine off.

It's been a few years since owning an FL1, but from memory the tail door window internal switch only works with the engine running. This is to ensure sufficient voltage is available, as the window has calculated positioning.
The rear window should drop about 20mm when the tail door outside switch is operated to allow the door to open, and should close again once the door is closed.
The tail door window should also close using the key hole in the handle. Both of these operations work with the engine off and the keys out of the ignition.
 

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