just got back from a 3100 mile road trip through 14 states, car ran like a dream, in the southern states with flat roads I was getting 23.5 mpg at 75 to 80 mph. now comes my problem after a period of ten days my key fob and drivers window stopped working again,easy fix disconect negative battery cable and do a hardreset. then same thing a week later, if any one knows how to fix this problem permantly I would like to find out how.thanks in advance jrb53 I forgot to mention this is my 2000 xj8 (x308)

 

thanks....you give me confidence that i can/should be able to take a long trip and return with my xj8/long-2000-
as re the problem you are having...i don't think its that uncommon to get the window problem to come up again...after you do a cold/reset...the fob/remote problem may or may not be related.

what i can say and after many posts on this issue is the absolute necessity of having a properly working battery. When was it last replaced?I would definitely have it checked out. I only mention this as the problem for me at least was resolved after i got a new battery last summer.good luck.

 

JR...these cars are designed for the open road ;o))
I did a 10,400klm (6,400 mile) round trip to Western Australia and it purred like a big cat should....even one stint where i tested the cars top speed ;o)
The car averaged 10.4klm/100klm which is 22.6mpg US and 27.16mpg UK

As has been mentioned, how old is your battery?
Have you replaced the batteries in your fob recently?
After you do a hard set, did you re-set the parameters for your window?
Open fully and hold switch for 3 seconds, fully close and hold switch for 3 seconds.
Fully lock the car, wait 10 seconds and then unlock the car....this should fix it.

I would definately have your main battery checked out....one thing these cars do not like is a dud battery.

 

I do have a newish battery 6months old and new for the key fob. will do the window reset and lock as suggested thanks