Mickey:
You are not finding the fuse panels because you are not looking where Red told you to look. The REAR HEEL boards. The REAR seat, behind the HEEL of your foot. Not the FRONT TOEBOARDS!

 

Yep, the elusive fuseboxes are behind the 2 carpeted vertical trim panels below the front edge of the rear seat base-exactly where your heels would be when you are sitting in the rear seat

You just carefully prise out the central plastic trim retainer (I use long-nosed pliers to lever it out) & then pull the panels forward from the transmission tunnel side-they have locating slots at the sill side.

 

I can sure understand him missing them, though. Who would ever dream of installing fuse panels there!

 

Here is a JPEG of the Fuse boxes Locations on LH Vehicle (Yours is RH Vehicle - not much difference except Engine compartment - item# 1):



Jim Lombardi

 

Hi Mickey,

I'm not a Jaguar Technician by any stretch of the imagination. However, I had a very similar problem with my 99 XJR recently.

The diagnosis procedure offered by Red October (12-07-2012, 11:54 PM) is spot on and is the process of elimination I also adopted, ie disconnecting each fuse box one at a time to find what one was still drawing a current after the electrical system should have 'gone to sleep'.

I was gob smacked to find that with all 5 fuse boxes disconnected I was still getting a current draw of 480mA which like yours was discharging the battery in a couple of days.

From the starting / charging circuit wiring diagram you will see that after eliminating the 5 fuse boxes there are only two items of electrical equipment left connected to the battery. The starter motor and the alternator (Connected in that sequence).

In my case, I disconnected the battery –ve and disconnected the alternator +ve output cable and taped up to prevent it grounding. Then reconnected the battery –ve and tested again for current draw which had dropped to zero. To satisfy that I’d found my fault I reconnected all the fuse boxes and waited for while with an Ammeter connected between the battery +ve terminal and the unconnected +ve battery lead. Hey presto! After about 3minutes the current draw dropped to just 23mA.

I think I could safely say that the alternators suppression module or voltage rectifier were faulty, which was confirmed when I replaced the alternator, which is a task in its self!!

FYI, In my circumstance there were no error messages thrown up on the IPK display and the ignition light went out when the engine was started. The only symptom was the battery not holding its charge.

Hopefully the above is of some assistance to you. Good Luck!

 

Chris, what mileage did you replace the alternator?
Did you have the old one checked or rebuilt as a spare?

 

Check battery ground and positive cables. If after running the + side is warm there is resistance and you have a bad cable or connection. Check the - side to make sure you have a good ground.

 

What a dingbat I am ,but what a place to hide them...hope to have yet another gander during the week.at the moment all boot trim is out revealing wiring & modules etc.
Thanks for all the help,really appreciated..
Regarding the jpeg of fuse box locations.the high power protection module is located on the inner rear panel(n/plate end) on mine and just one engine compartment fuse/relay box.
I'm new to this forum,was going to post some photos but couldn't work out how to post them....I am using iPad .

 

In relation to the 'going to sleep period' what should the drain be and for what length of time should this be ??.

 

Xjay8,
My 99 XJR was two years old when I took ownership with 19K on the clock. I doubt the alternator was replaced before I bought the car but can't say for sure. However, I replaced the alternator at 114K. Hope this answers your question.

Mickey,
I believe the Jaguar specification for the XJ8 'going to sleep' is 60minutes from setting the alarm. After this period the quiescent drain should not exceed 30mA. When I tested my car sleep mode took only 3-4 minutes to drop the current drain to 23mA, but can offer no explanation of why Jag state 60mins or why mine took only a fraction of this time.

I would imagine the 30mA stated by Jaguar does not include accessories such as mobile phone cradles, Sat/Nav devices, tracker devices and the like.

 

The alternator can fail in 2 ways & draw current when the other systems are all shut down:

1) The suppression module could be leaky-internal capacitors may have a leaky dielectric.

2) The main diode rectifier pack may have leaky internal diodes which are starting to break down. The alternator can continue to work normally & no throw up any fault codes-it just leaks a small amount of current away which adds up to a flat battery after a few days.

Both these components are permanently 'live' & so will draw current even when the ignition is switched off.

At least you've found the elusive fuse boxes though

 

Mickey,

Red October is spot on!

A quick bench test of my old alternator using a multi-meter confirmed that the rectifier / diode pack had a high resistance leakage to earth (ground). I also had no warnings or error codes and the car drove fine (apart from another issue I'm having) and charged the battery. The only symptom was a flat battery if the car wasn't used for 2-3 days.

As a quick process of elimination I recommend you isolate the 5 fuse boxes then see if you still have any current draw. As Red October states, the alternator and starter motor are permanently connected to the battery regardless of the ignition switch position.

FYI I did try to locate a service kit for my alternator but there doesn't appear to be one readily available that I could find. A 'new' unit cost me £170.00 on ebay, (quoted £280 from Brit Parts & £420.00 from Jaguar). So if the alternator is your problem shop around!

 

A service kit is not necessarily required.

The alternator is really a Denso using off the shelf components. Some of those Denso components can be repaired using off the shelf parts. Most old time alternator repair shops will have them if you drag the parts in for comparison. The individual parts can be found separately on ebay by searching the part numbers.

The last Denso that packed it in was "rebuilt" using the following parts:

2 brushes @ $5 installed
1 regulator @30
2 diodes @ 10 installed

The shop did not stock either brush assemblies or rectifier packs because it is cheaper for them to just repair them.

edited to remove error: "The Jaguar alternator does not use an onboard regulator so that cost would be eliminated."

 

Plums:
"The Jaguar alternator does not use an onboard regulator"
Are you sure about that?

 

Good catch.

That's what I get for repeating others.

You're right, the wiring diagram shows an integral regulator. Just flipped the screen because it was already open anyways in preparation for a power fold mirror upgrade.

 

I have the same problem ,
I already bought a new to expensive battery and the ... seller kept my old probably good battery ,i hate it when people lie .
I already have the altenator out of the car {took of the inside fender to take that out} the test shop says it was ok....but now i have my doubts
Tomorrow i do the fuse box check and again the altenator ..
I,m really getting anoid when after two days the battery is dead .
Ill keep you informed ,hope i find the problem.

 

The voltage regulator is in the alternator, but it has it's own external +12v supply which is energised with the ignition switched on.

I would suggest checking the +12v supply to the regulator first-it comes from the engine compartment fuse box via fuse number 2, which is a 5 amp unit. Check if that fuse is still working, because if it is blown then the alternator regulator will not get it's +12v supply & so the alternator will not charge.

 

We measured the battery and my mechanic found that the Jaguar/Motorola telephone module unit in the trunk is warm .

We unplugged the module and immediatly the meter dropped from
0.25 to 0.07.
I think there is a problem in the handset or module .
I never use that phone so i dont really miss it.

I also unplugged the handset under the armrest and hope the problem is fixed,it probably is.... it now sleeps at 0.05