Hi,
I have a 1997 XJ6 (that I infrequently drive - just use it a few times every few weeks) with the following problem:

After parking the car the driver side rear window (sometime later) went down by itself.

I discovered that a day or two later and it would not go up with the master switch nor the individual switch on the involved door.

I started the car and went for a little ride and it went up - all was fine.

A few days later I came back to the car and the window was down and the battery was dead.

I tried charging the battery but that wouldn't work so I jumped it and it started. The window still would not go up.

I drove the car a bit to charge things up and turned it off and tried it again and it started.

The next morning the battery was dead again.

I took the battery to an auto parts place and they charged it and tested it and reported that it is in good condition.

I put it back in the car and it started but the window would not go up.

I put a "battery tender" on the battery and left it for about 3 days. I just tried to start it and the battery is completely dead again.

I have changed the CPU two times in the last 7 years. The last time was about 3 or 4 years ago.

I'm looking for suggestions on how to proceed?

Thanks,
Ron

 

Intermittent problems are hard to diagnose. Could possibly be a faulty power window switch or a bad BPM. I would first try swapping out the switch with a good used one and see if the problem persists.

 

Are you able to measure whether there is any current being drawn from your battery when the key is extracted from the ignition? If you can and there is a current being drawn, start pulling fuses sequentially until you identify the circuit drawing the current, and work back from there.