Welcome ,
I can't be any help of your all queries nor can I shed some illuminating lights w/ my reply but I think I can answer at the last part of your message which is related to your A/C . What you are hearing when you stop your engine is a fan sound , it runs a few secs even after you stop your engine .
In older Jags dating back to Series III , that unit stuck open and hence a drained battery .
Don't worry I hear a similar noise too .

 

Hello MRDCON,

Also note wich gear you in. The automatic in non-J-gate upshifts pretty fast to save gas and can make a hum at 30--45 MPH,

 

"I also have a sound coming from the climate control area of the dash." I have the same and was about to dismantle the dash when I found a previous post https://www.jaguarforums.com/forum/s...oto=nextnewest
saying it is indeed "normal". It's supposed to last up to 30 minutes after you turn off your engine.... I'm gone check out that 30 minutes theory tonight with my wife remembering the younger years of our love!!! Results tomorrow!

 

So, I did sacrifice myself and made the test. We went in the car and the humming was present. I put the key in, listen to a song, played around with the seats to get comfortable... removed the key and shut everything off. The humming was still going on. Precisely 12:00 am on the clock! The waiting test began... I think it wouldn't be appropriate to describe the exact nature of the waiting time in the Jaguar Forum, maybe somewhere else, some other time... and then it happened: the Humming noise was gone! I took a brief recess from my waiting activity (which seemed quite short), quickly put the key on ac to check the time... precisely 12:30!!!!! OMG! Putting the key in the contact didn't restarted the humming but as soon as I cracked open the door: humming noise was back! The theory stands confirmed. Now, I do have two good reasons to go to bed happy: There's nothing wrong with my Jag (at least not THAT!) and you know, I'm glad I waited! In resume: Weird humming noise, motor like sound, electric shaver noise coming from the dash... NORMAL!!!!

 

I also have noticed a very low grade humming /buzzing sound after I turn the ignition off, and either leave the key in or remove it. It is originating from the steering column area, and kind of sounds like an electric current running through something. But with the key removed, there really shouldn't be anything on. I am concerned that something is draining the battery, even though this thread has confirmed that this is a normal sound. Does anyone know exactly what is causing the sound? Thanks in advance for your help.

 

That is a small aspirator fan. There is a small square that looks like a small vent. It might make noise if it gets dirty. Maybe if you blow it out it will quiet down. It will stay on like a half an hour. It is perfectly normal. If you do a search on here there are a number of threads that go into more detail of how it works

 

It is indeed the aspirator fan and the system is designed to prepare the cabin for quick temperature stabilization through the climate control operation. To that end, the INSTANT the driver's door handle is pulled, the fan goes into operation. It remains in operation constantly until a programmed period of time after the engine is shut off (this compensates for those trips in which you makes multiple entries and exits from the car). You cannot verify the operation of this programme unless you sit in the car for a half hour after shutting the engine down!
The climate control system was designed for Jaguar by Denso. -the best...and they design the climate control systems fir a variety of marques.

 

Post #3 =

https://www.jaguarforums.com/forum/x...d-dash-214328/

 

Once again, the jaguarforums come through. Indeed the numerous threads seem to describe the exact buzzing issue I was asking about. I will try to refine my search technique for the future so I don't have to bother you all so much. Thanks again.