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Hi.
Having installed the remote and one touch convertible top gadget from the Jagwrangler ( brilliant and easy to install by the way) I then turned to installing a navtv module to enable a reversing camera that would appear on the factory nav touch screen.
No real difficulties here either except that the instructions for a vehicle specific item ( in this case XK and XF) are extremely vague.
I have it installed and working fine but I have a multi part question that hopefully forum members might be able to help me with.
I have tapped in (using Posi-taps) to the red wire supplying 12v to the nav unit in the boot.
To my mind this must be on the circuit that powers up when the car is unlocked and will power down when locked again.
You do not need the ignition on or the engine running to change the nav discs for example.
When looking for a suitable switched acc +ve 12v in the boot it occurred to me that it would be logical to use the supply for the nav unit so I unplugged and put a test light on , 12v present. I left the light connected and trailing out of the closed boot and locked the car to see how long power would be present. I thought it would only be a couple of minutes but maybe 20 minutes had passed and the light was still on.
Needing to get on I disconnected the test light and completed the installation and put the car back together but this power thing is niggling.
The question.
A) Does the nav unit stay powered for a limited time after locking?
B) If so anyone know for how long?
C) Could I cause confusion to the cars brain by tapping in to this circuit that might prevent a power down?
I had a B6 Passat as a work everyday driver that I installed an after market nav,& camera unit in to that somehow prevented the car powering down a few years ago. Apparently the car would keep looking for its own head unit preventing it from going to sleep. I am hoping that this installation is not in any way similar.
I do not seem to be having any battery drain issues ( I fitted a new one while I had the car apart anyway despite the 7.5 year old seeming to be perfect) since finishing the job a couple of days ago.
Hoping someone can advise...

Some of the car's circuitry remains powered getting on towards an hour after locking the car. This is the minimum time Jaguar recommends leaving the car before carrying out a quiescent current test. I would suspect the sat nav unit is among the affected circuits since it's quite likely to be used whilst the car is stationary. Equally, there must certainly be a risk that taking power from that circuit will keep it alive. It's possibly a question you should pose to XJK or David Marks who are both brilliant at electronic diagnostics and work with similar issues on a daily basis. Try dropping one of them an email. It would probably be more convenient than locking the car and leaving it for 3 weeks to see if the battery goes flat! Mike.

Update.
I sent off emails but have not yet had a reply.
I also contacted by telephone Nav- Tv . I was passed on to someone " even more expert". He did not have a clue except to say we usually advise a switched acc connection. This I knew but needed to know if there was one in the boot where the module would logically be installed as the nav ' computer' is located there.
Anyhow I have not as yet had an answer to my query but wanted to get on with it.
Convinced that there was battery drain the way it was connected I have moved the connection.
The power to the nav I am guessing is : red - battery power ( for memory) , yellow - canbus 'on'. No good for this application.
So I set away to find a circuit that would go live at key on and off at key off.
Boot area - no joy
Behind rear seats?, well there is a supply that is apparently ' Acc B+' which I guess is for those cars with a rear accessory socket ( mine hasn't) but it did not seem to go ' dead' at key off - so no good.
Next thought would be the ' cigar lighter ' circuit but I could not get at the back of the socket without more dismantling than I was prepared to do and there were several ' blue and white' wires- the right colour- accessible anyway none of which seemed to be the right one.
Ultimately I identified the black and white wire that supplies power to the glovebox socket which is accessible via the passenger side dash end cover ( on the lower green coloured multi plug ).So I have gone from wishing to keep it all together in the boot to having to connect at the last stop before the engine bay.
Never mind - got there in the end. All working and no battery drain.
Was it worth the cost and effort?, probably not but hey ho got to do something as a pastime and I don't play golf.
As regards the connection method I would not normally use any other method than soldering but being impressed by the Posi-taps as supplied by the Jagwrangler I decided to use these and found a supplier online.
They work well and are pretty foolproof with the added benefit of being easily stripped out again leaving no damage other than a prick hole in the insulation - and no precarious balancing of a hot soldering iron.

I am interested in doing this to my 2008 XK Convertible. Could you please give a little more detail as to which Nav-TV camera you fitted, whether it just plugs straight into an existing socket on the Navigation Display Module, where/how you attached the camera, and what other tasks were involved? Many thanks in anticipation.

Sorry that I can't really help you with Nav-TV details, but I'm surprised the OP had so much trouble locating a suitable ignition switched supply at the rear of the car. Jaguar provide a spare accessory socket on the left-hand side of the boot, behind the carpet liner panel. It's coloured Black and contains three male spade connectors - Black wire is to Ground, Brown is a permanent battery supply and White/Red is the ignition switched supply. Each of the supplies is protected by a 10A fuse. A wire with an insulated female spade connector can be pushed onto any of the three points in the connector to put it to use.
If you need a supply at the front, there's another spare accessory connector, Black (early years),Fawn (later years) this time and with only two wires; Black for Ground and White/Black for Ignition Switched supply, again with a 10A fuse. It's tucked up behind the glovebox that has to come out for access.
Hope that's some help if you can find out the rest!