2 days ago, both door windows won't raise or lower. This error was detect at the same time. No OBD codes were thrown. No fuse in the left and right fascia fuse compartment has blown.
The driver-side window (my XK8 vert is RHD) will make a drop when the door lever is pulled, but will not rise when the door is closed. Did the overall reset by disconnecting the lead to the battery + terminal and grounding it, but to no avail.

What is happening, please?

 

Often caused by a failing battery. And sometimes caused by failing microswitches in the door latch assemblies....

 

Thank you Jon89 for your reply.

The battery is in great shape. Otherwise many other faults relating to a failing battery would have also surfaced.

How can I determine if the door latch microswitches are at fault? Do I have to remove the door panels to get to them?

 

Yes, you must remove the door panels. There are multiple threads here on the forum that explain this job in detail. The microswitches are inside the door latch assembly. Small hands are required for some of the work inside the door....

Some of us have sourced our more robust replacement microswitches at www.mouser.com. Always a good idea to order at least two (one is required for each door). The part number is Omron D2SW-3L3MS.....

 

Thanks Jon89 for the replacement microswitch part number.

Before removing the door panel and the door latch, is there any POSITIVE diagnostic to pinpoint the window winding up/down fault really lies in a faulty door latch microswitch?

As a side note; when my roof switch failed, I was able to manually lock down the roof by manual/mechanical means; the left and right quarter windows were closed by shorting the relevant relay contacts of the drive motors. The door window motors are driven directly by the Door Control Modules and not with relays; I am tempted to directly apply power to the window motor to raise the window as a temporary measure. What are the risks involved here?

 

I cannot say there is a positive diagnostic to prove that your door latch microswitches are indeed the cause of your window issues. What I CAN say is that for the vast majority of owners who have reported this problem during the past ten years or so, if a new battery does not resolve their issue, the proper (and more robust) replacement microswitch in the door latch fixes it....

I cannot speak to the risks involved by applying power directly to the window motors. I have never done so....

 

Please RESET the window limit settings!!!!!!!!!!!!!!!!

LOWER the widows fully.
HOLD the window lift until fully closed and CONTINUE TO HOLD UP switch.

You will hear a faint 'click'.
DONE!!!!!!!!!!!!!!!!!!!!

If you disconnect the battery you must REPEAT the settings.

 

^^ Bob is correct. Do this on both windows if you have not done so already. I try to remember to reset the windows in my wife's XK8 at least every month or so just to keep them working properly....

 

Thank you so very much to everyone who has responded.

Before tearing the door panels to deal with the suspected faulty door latch microswitches, I did one last check of the fuses in both the driver-side and the passsenger-side facia fuse boxes. I found a blown fuse Fuse #4 5 amp on the pax-side facia fuse box which I had missed detecting on my previous check; it supplies power to the window switches to send to the Door Control Modules, thus effectively disabling both windows.

All windows are now functioning normally after fuse replacement, and after they've been retrained as per the last two replies.

December, January and February are the best months for open air motoring in Hong Kong as the 15~20 degree C temperature and ~50% relative humidity with plenty of sunshine weather, so I've been dropping the roof as often as I can. My XK8 vert has also been authorized since last year to go into China's Guangdong province via the magnificient ZMH Zhuhai-Macao-Hongkong Bridge. Mainland Chinese are totally unfamiliar with my Jag as there are so very very few of this ancient beast around in China, so I was constantly asked by bystanders for permission to take photos of the Jag. I have also gotten accustomed to driving my RHD vehicle in China which is LHD.

A secondary benefit of driving in China is to take advantage of the cheaper cost of refuelling petrol there; it only costs half as much as it is in Hong Kong due to very high tax on petrol in Hong Kong. So I always bring a full tank upon return to Hong Kong.

I would gladly take any forum members visiting Hong Kong into China with my Jag. Do take advantage of the recent the Chinese government 10-day visa-free allowance for passport holder of many countries to visit all parts of China.

Cheers.

 

In my experience the window problem is the first thing to show up a weak battery that otherwise seems to be in perfect shape.

 

^^ Same here....