Almost everytime I get in my 2000 XK8 conv. the windows have to be resynced. Easy to do but this hasn't been the problem before except when the car sat for an extended period. It is not sitting now. It is driven almost daily.

I am suspecious that it might be the battery showing it's age. Except for the windows everything else works fine. Not sure how old the battery is but pretty old.

Any other things that could cause this?

 

I would suggest having the battery tested.

 

+1

In a daily driver, it's usually an early warning sign of a battery on the way out.

If you still have the OE battery, the manufacturing date code will be stamped into the top of the terminal post:



Code is WW-YY. This one is Week 23 in 2012.

Graham

 

Not the OE battery. Voltage stays slightly above twelve volts. Is that system that sensitive?

 

Window memory is often lost when the voltage goes below 10.5v and this could take place after the car has been sitting for a few days or just after an engine start. If you checked it with a volt meter that is not a good test. Take the car to Sears, AutoZone, :PepBoys or Advance Auto and get them to test it under load.

 

Starting the engine is enough to pull the voltage down enough to affect window memory. That happens to me a lot. Always due to a marginal battery and/or low state of charge. I added some solar panel boosters, but that wasn't enough. Now I've started installing battery disconnect switches to all my batteries if I'm going to park them a few days. Of course, that guarantees window setting is lost, trip computer zeros, and clock stops. Having a marginal battery was OK on simpler cars, but not on an XK8. In addition, I top up charge my batteries on occasion if I'm not driving the car enough.

 

I was having the same issue, and I posted a thread about it a few months ago. Someone told me to check the battery voltage after the car had been sitting overnight. As I recall, 12.5V was the tipping point. My battery read 12.6V. I replaced it (Jaguar branded, so likely original and 10 years old), and the window problem was solved.

 

This must be the 'Year of the Battery' - I've lost count of the number of replacements reported on this section alone.

Good news is the number of spooky electrical issues fixed as a result.

Graham

 

I agree Graham. I had to replace the batteries in both Jags within a two week period. The XJ6 went totally dead with a dead cell so that was obvious. And the window syn problem was a good indicator for the battery in the XK8. And yes, a new battery solved the window sync problem. That was a pretty good indicator.

Thanks Graham.