Ok, I have read many threads on window drop and the associated symptoms and fixes.

2005 xk8 convertible 69k miles all systems operating correctly until this happened.

Window drops properly when handle is pulled, then when the door is opened the window drops again approximately the same increment. When door is closed window does not raise automatically.

I had the driver's side lock mechanism out and it is clear that the window drops when either (the latch switch or the handle lever switch) micro switch is triggered.
In addition the incremental drop continues each time the handle is pulled. In other words the window can be completely lowered if the handle is operated, lift,drop, release,lift,drop, release .
This happens both when the door is open or when the door is closed.

The only time the windows raise is using the window switches with the key in the run position.

Now for the fun part...these symptoms are the same for both doors. Just to be sure, I swapped Door modules driver to passenger, passenger to driver, and symptoms did not change.

Any ideas?

It seems unlikely that both door modules failed in the same manner at the same time.

Just some thoughts on the proper operation as I understand it:

When latch micro switch indicates door closed, lever(door handle) micro switch triggers window drop. Door is opened and latch micro switch opens. In this state operating the lever micro switch does nothing. When door is closed the window raises. Sound right?

 

Searching the web I found this from a forum called roadfly dated 2006

Jag xk8 window problem any help

[I]"Hi,

Not sure if this is your exact problem but might help:

Most if not all old shape XK's have issues with the windows dropping when door opening and not returning to position - it's not a fault with the car as such, all that happens is the relay "forgets" where the top and bottom positions are. This usually happens if the battery is getting low, or if car has been stood for ages. Thankfully there is an easy cure:

Firstly, make sure your battery is fully charged / buy new battery if old or knackered.

Now sit in drivers seat with power on and doors shut. hold both window buttons down to lower windows, and keep held down until a second or two after window has lowered, and you will hear a click - this is the relay resetting. now hold down buttons in the up position all the way up and wait until you hear a click again - relay resetting top position. repeat this a few times for good measure, and this will reprogram the relays, and things should be fine.

I explain this to any customer buying a used XK from me at handover, as it usually starts happening at some point and if they know beforehand it stops them from panicking!

Hope this helps![/I]


It actually worked. My windows now operate correctly. I am also very familiar with the assembly and disassembly of door. And I can take off a door card in under 5 minutes.

 

You MAY find it's not a solution but only a temporary fix.

The door drop scenario you describe is a regular early indication of a failing battery.

Graham

 

^^ Agreed. A failing battery is always the initial suspect....

 

Thanks for the battery advisory. I will check it today when I go out to put the interior back together.

Derek

 

Equally, that resetting of limit relays is documented here somewhere. Did you use the forum's Search tools and "How To . . . " Stickys. Not unique to older models and yes . . . a sure indicator of a sick battery and another great prompt to use a smart charger during low use periods.

Cheers,

Ken

 

My battery's on it's last legs, but the car sits for long periods, so I've avoided buying a new battery and just having it sit, I do have a battery tender.
I can do a reset and all is good but after two or three start stops it back to ever dropping window!