There are old threads about this (maybe Search will find them if you try) with suggestions how to go about diagnosing and fixing the issue.

 

Check this service action

S414-01
S-Type
DATE 6/99
Amended 05/00
MODEL
2000 MY-ON
S-TYPE
VIN
L00001-ON
Battery - Quiescent Drain Current - Specifications
Remove and destroy Bulletin S414-01, dated 6/99. Replace with this Bulletin. The entire test procedure has been revised.
Issue:
This bulletin provides specifications for quiescent current drains from the vehicle battery, as well as a procedure for measuring them using a digital volt/ohmmeter (DVOM).
Action:
CHECKING QUIESCENT DRAIN CURRENT
Note: The four (4) Switched Power Relays in the Rear Distribution Box will stay active until the last SCP message is sent. This process will last up to 30-40 minutes. Opening any of the doors or the trunk during the Quiescent Drain Test will cause the timer to reset and delay the shut down of the relays. It is also recommended that the battery isolation device remain attached to the battery and NOT be removed until the vehicle is ready for delivery to the retail customer. This will prevent unnecessary drain of the battery and inconvenience to the customer.
Record the following system settings prior to disconnecting the battery so that they may be reset to the customers preferred setting.
^ Clock time setting
^ Clock 12/24 hour setting
^ CD compress mode (if equipped. Radio must be in CD mode to check this setting.)
^ Navigation volume defaults to 14 (if equipped)
^ Voice feedback volume defaults to 14 (if equipped - voice training is not lost).
^ Gear box mode
^ Radio presets AM/FM
^ Compass calibration and zone setting
^ Navigation memory will be retained if the battery has not been disconnected longer than 24 hrs.

The trip computers (both A & B) will reset to zero, these however cannot be returned to prior readings.
Use a DVOM as follows to measure quiescent drain current:
1. Disconnect the battery negative cable and check the battery off-load voltage. If the voltage is below 12.5 volts, recharge the battery and retest the voltage. If OK, reconnect the negative cable.
2. Rotate the ignition switch to position II and leave for 30 seconds, then turn the ignition off and remove the key.
3. Ensure that the exterior light switch is turned off, the radio is switched off, the mobile phone (if equipped) is also turned off. Ensure that the interior light switches are turned off.
4. Close all the doors, and the hood. With the trunk open, move the latch to the closed position. Disconnect the trunk lights.
5. Disconnect battery negative cable. Connect a DVOM between the negative cable and battery to perform the test. The vehicle's alarm system and radio will default to active when the battery is reconnected. Press the key-fob transmitter to disarm the alarm. Turn the radio off.


6. Measure the quiescent current drain. The expected readings are as shown.
Note: All the above figures are approximate and can vary from vehicle to vehicle.
However, after 45 minutes the quiescent drain of any vehicle equipped with Jaguar-approved accessories should be no greater than 30 milliamps.
If the test is carried out with the security system in its armed state, the drain should be approximately the same as the readings above, but there will be a pulse to 46 milliamps for 0.25 second when the LED flashes.
Always ensure that a 'clean' connection is made when connecting the battery. If a temporary contact is made, disconnect, wait 60 seconds, then reconnect cleanly
Warranty Information:
This Technical Bulletin is issued as a guide for information purposes only.

 

Gentleman

This looks like a very relevant post for me, as my car has drained its battery if left for more than a week to 10 days.

One question though - if you open the trunk to access the trouble shooting area of the wiring - does the car not draw current again?

I will look into this on mine when I get a chance and report back what I find.

Regards
Pete in Toronto



Pete
When I am diagnosing the S-Type battery drain faults I open all the doors and click the latches SHUT so the car thinks the doors are closed. I put a flat stick in the boot lid switch under the plastic liner to simulate the boot lid closed. You can now watch the ammeter in series with the battery to see the current draw diminish as each module shuts down. If after 40 minutes you still have more than aprox 40ma then you can unplug fuses or modules to find the faulty circuit. Be aware that when you plug or unplug a fuse or harness you might 'wake the car back up' and then you have to go through the waiting period again. You might find it quickly or it may take many hours. good luck

bob gauff

 

Bob,
I was looking for another resource on a problem with the wiring harness chaffing in the right rear quarter panel but I cannot find it. If you are at the battery remove the interior panel to the right facing forward and you will see the wiring harness going forward. What I recall is that it is resting on a bad spot and is a matter of pulling a little slack. I will continue to look (feeling under the weather today) but will let you know if I can find it. You tell me what you find!

 

I went through the same as a new member.Find h20boy postings and as said.Click on his lower sig or what ever that it is called at the bottom right hand of his postings.If you do a search on my postings you will find him fast.h20boy seems to be the only one in computer Jag. land that has helped me.Great person at any rate.
Folks have to keep in mind this older "better"generation is not so as the young of today.They have grown up with and never had to be told get a dictionary if you do not know how to spell something or have to go to a public library to check out a book if you need information on ANY subject.They are all spoiled little because of.
I wonder if in the long run,has the computer done us any good or if the drop out rate is higher because of?This is the new drug.I know that I can spend all day and never get a thing done.And have gained 40 pounds!Ok lunch time .

 

Bob, Thanks basically I have to trick the trunk (boot) close switch.
Not sure when I will get to this, but very big help.
Pete

 

Why not do it when you get home? Besides, to test you first need to wait 40-45 mins so the modules SHOULD have shut down.

Could be glove box light or any other switch/connector (door, you name it!) which isn't working right.

 

looks like I am going to get into this sooner than expected - went out this morning not having driven the jag on the weekend, and starter wouldn't go.
Good thing I love driving my Tbird SC!
Found a local guy with an S type parting out - going to check part numbers on the modules it uses, while I diagnose with my DC mili ammeter.
Pete

 

Is there anywhere to boost under the hood?
Cam home from work to charge, now completely dead and i can't open the trunk (I mean boot)....
In the past I have got in through an incompletely latched back seat, but it is firmly latched right now.

Pete
I don't have JTIS running on any of my computers right now due to switching to Windows 7 in newer ones....
Also, considering it is a used car - it is possible there may be a tracking device - I am asking Boomerang how to determine if this car every had one which COULD possibly be drawing current.

 

Use the key in the trunk it is mechanical! If you only have the valet key you can look at the oneline for your car and look at the power distribution and you will see points under the hood that you can connect to. If you elect to do this with another battery use caution! Failure to do it incorrectly could be a real problem. Use the attached link for your cars onelines.

http://www.gusglikas.com/AutoRepairElectrical.htm

 

Thanks Gus, I had tried the key a while ago, and didn't get the impression it was mechanical, didn't want to force it so stopped.
I'll try a little harder now.
Thanks
Pete
(would seam very odd that there were no mechanical way to get into the trunk, but given key shape as well I didn't want to force it).

 

Gus
I found S414-02 if that is what you are refering to.

bob gauff

 

3:30 am can't sleep so studying this a bit....
Looks like if I can detect a current draw, that pulling the 4 system switched relays out of the rear fuse box should kill the draw if it is a fault in the front or rear electronic control module pulling them closed.
I also notice the TSB about the current jumper across the firewall as a possible source of fault.
Will try to look at this tomorrow. I boosted the car from my Tbird and held the Tbird at 1500 rpm for about 5min, and this was enough to take the battery from 3v to starting the car just fine - which seams a bit odd for the battery to recover so easily. The Jag's battery is only 1yr old.
Will post as I progress thanks all
PR

 

PDR1966 Keep us informed of your findings! In the meantime I am plugging the battery to a trickle charger every night. Getting used to what I guess we will all do in a decade from now! plugging your car to an electric outlet

 

Bob,
You found one but it was not the one I was looking for. I just now found it, it is bulletin S100-05 and it addresses several things. The rerouting of the main body harness and the replacement of the mega fuses in the trunk along with a few other things. I am unable to get it right now but will try when I get home and post it then.

 

This is the latest S100-05 that I have!!!!
I don't think it was amended since!!!

bob gauff

 

Bob, You are the man!

 

without going through all these 39 posts. I can tell you that all the issues as of the past 4-5 years for battery drains that are intermittent have been the elctrical portion of the ignition switch. its cheap and not hard to change. The switch gets crossfeed of power occasionally and the car wont go to sleep. When the battery voltage goes down enough, the car fully wakes up and runs the battery down the rest of the way

 

I will say that this is also what I have seen.