99 xjr driver window and sunroof lock at what seems to be cold start up. removing the neg cable fixes problem but does anyone know why this is happening?

 

That is a strange one -- I can't think of an interlink between only the sunroof and the one window?

The sunroof has a force limitation built into it so if it tries to open and can not it will stop.


Do you hear any sounds when you first try to do this?

 

when this happens the engine start but on last crank there is a double click form the starter and a hesitation...you can hear the driver window motor click but no reaction and the roof will open but closes after a few seconds.

 

How old is your battery?

If it is weak when you start the car the starter can drain the battery -- the volts drop and all kinds of strange things can happen.

On the sunroof the tracks need to be kept clean and lubricated with the proper grease and it need to be done correctly. Even with a new battery the roof can stop if it needs this service -- but is an early indication of a bad battery.

Strangely these thing can continue after the car is running and the alternator is working correctly. Very strange car with a weak battery.

Good luck

 

battery is only about 6 mths old and high on the cold amp cranks

 

If you are saying that the window and roof do this independent of you touching the buttons and this happen only occasionally when the starter motor does this double click then it has to be the starter motor pulling too many amps or corrosion someplace in the electrical system.

Have you looked over the main positive power connections -- especially the one coming out of the computer box in the engine compartment on the passenger side at the windshield?

It sounds like the electrical system is getting a momentary low volt situation.

 

I bet yeldogt's got it -

"Have you looked over the main positive power connections -- especially the one coming out of the computer box in the engine compartment on the passenger side at the windshield?"

 

no its not independent if the window or roof is engaged nothing happens but u can her the switch on the window click as in energizing dissconect neg for soft reboot and back to normal. am just wondering if this is one of jags little fix this if this sequence of events takes place since its localized to start up and only the driver window whereas other 3 work fine

 

Whatever is happening to the control modules must be coming from the poor start condition -- so that is what you need to look at -- as it is not going to fix itself.

Maybe it is effecting some module that is designed to be always energized and the poor start causes a fault - only corrected by removing power and then reenergizing. This is the nature of electronics - not Jag specific - although the Jaguar electrical system is complex so it lends itself to this kind of low volt problem.

When my battery was failing last time - I went to start the car after it was sitting a few days and it did not crank correctly - all kinds of warnings came on and stayed on until I was able to shut the car off and restart it. I have also had the power locks go crazy when you go to open the doors.

The other thing that can be happening is your alternator could be going. This can be strange since you can drive it normally on some days and all is well and then drive it at night with the lights and wipers on for an expended time and then park it -- actually you have drained the battery and when you try to start the car next you have a low battery condition.

 

put my volt meeter on battery with engine idling and lights on read 14.1 consistent so I feel the alternator is good gonna run a cell test on batter to see if its not taking full charge. Also noticed that I have a small belt noise developing from what I can tell at quick glance it's the super charger belt. Belt is in good physical appearance and the supercharger was torn down cleaned and roiled about 9 mths ago.

 

are you seals on the sunroof and drivers window moisturized? try greasing them up a little bit, i had the same problem with the sunroof

 

yeah....everything works fine after a soft reboot until the next time I get a volt jolt at start up. No codes and no warnings

 

the exact thing happened to me and a couple days later it cleared up and that was a month ago.I did check all my fuses and found none blown.I now have to engage my foglamp button to get my tail lights to come on at night when I put my headlamps on only they don't work .also my foglamps don't work either.not that they do anything significant.this is a quirky auto but it's exciting to see whats next.