Hello all! I have searched around, I believe thoroughly, but have not seen this issue posted.
I have 2005 Super V8 (yay!)
Brand new (and tested again now) battery
I added Bluetooth phone from 06 (trunk module and floor console Bluetooth receiver/adapter).
I now have parasitic drain, 2.5 amps. I followed directions regarding quiescent drain to the best of my abilities. Ended up pulling every fuse in the whole car (except mega fuses). Amp draw never below 2.1.
Pulled in garage and discovered every button is Illuminated even after full security locked for 40 min. Includes overhead console buttons and little orange shifter light.
Park brake switch, gauge cluster, dash clock not illuminated.
Absolutely every other green backlight is illuminated: front and rear, window switches, air register main cutoffs, orange grab handle lights, j-gate, steering wheel etc.
Please help!

 

I'd undo the work and check also for any chafed wires etc

 

I checked for chafed wires as I was doing the job, I'm treating it like a restoration project. But I'm leaning towards trying that, because it would be Occam's razor vs the FEM
I should add: as I returned the overhead console after adding the mic, I think there was still some electric cleaner in the main Interior lights button, it smoked a little and now that button alone does not function. All the lights/lamps still work in Auto mode, just can't operate the button.
Could that have fried a very specific part of the FEM or something?

 

In the future, never ever use anything to clean electrical controls other than Radio Shack Contact Cleaner & Lubricant (Cat. No. 6400148) as it's 100% safe on plastics and excellent for revitalizing electrical controls of any kind. If that main interior lights button smoked, then it certainly should be checked for damage and/or replaced.

 

After more reading in the shop manual, I formulated this:
Hypothesis: The FEM activates lights by grounding the circuit. So if the circuit is grounded/complete, (lights on) not requiring any further influence to stay on, then pulling every fuse would not shut off the lights. If the FEM is not powered to complete the interior illumination circuit, then the quiescent drain will not be present.
Control Test: connected battery, observed interior illumination on, remove F42 (Fuse 42: FEM, REM, DDM, Clock) passenger junction box, observed interior illumination was indeed still on.
Test: left F42 removed, disconnected battery, installed ammeter in series of battery and ground, observed amp draw reduced to standard 0.03-5 amps implying full sleep, observed interior illumination was not active.
Plugged in F42, interior illumination circuit activated, remove F42, amp draw maintains 2.5-2.6 as before and int. illum. remains powered.
Conclusion?: is my FEM fried to always complete the interior illumination circuits?

 

No ideas out there about the FEM or anything else?

 

CDC has a contact cleaner and lubricant (plastic safe) that I've been using for years. Big Box stores have it in the electric department next to 'contact cleaner only' products, compressed air in the can, etc. The nearest Radio Shack around here is 20 miles away and leases space from a cellular phone store.

 

Took the car to the dealer, explained the situation and grilled them with my other questions.
Dealer foreman told me the diag got many codes from the FEM that even the dealer system couldn't read so most likely it needs to be replaced.
So, call me an idiot, but I have a donor car so I swapped the FEMs and... No change.
So I systematically undid every change that I made, (overhead console contact cleaning and mic addition, trunk phone module and floor console blootooth adapter module) one at a time, checking for the issue to persist with the "new" FEM. Nothing changed, the illumination stays lit from the point the FEM gets power to when the battery is disconnected.
So I assume the issue is something else calling for that circuit to be completed and the FEM is just obeying. Any help?

 

It sounds like there might be a rogue electrical ground somewhere, and likely located in the areas where you were previously working. Actually, that smoking main interior lights button still bothers me.

 

I agree about it being rogue! Lol.
But as I disassembled my changes I left everything unplugged so that if the solution was triggered I could reassemble the recently disassembled components one at a time to ensure I had found the only problem. I say all that to say: the entire overhead console is completely disconnected and the problem persists. I need to try to narrow down what affects the circuits for the illumination. I believe it is indeed multiple circuits.

 

After more reading and searching and another discussion with my Jag dealer I was uncertain if there was a proper illumination module. I believe there was one on the x308 and I found some evidence that the instrument cluster switchpack and dimmer might serve that purpose. So I checked all of the associated fuses with the same method I used for the FEM F42 (disconnect battery ground, pull fuse, reconnect ground, observe illumination).
No effect. So I removed the instrument cluster switchpack and dimmer and tested, no change.
I'm really drying up on ideas! Could there be a short between the FEM and some accessory that calls for the FEM to activate the illumination? That is still the only thing I can remove power to and fix the power drain.

 

Following and thinking

 

Used "Voltage Drop" across fuses to try to narrow down a path to check. It was inconclusive as the main things getting power are exactly what I expect, (as I understand it) the light circuits:
Cabin Fuse Box: F14, 10A, Courtesy light, footwell lamps, rain sensor, FEM, autolamp module
Trunk Fuse Box: F11, 5A, Rear footwell lamps, grab handle lamps, overhead console map lamps. I did try removing the autolamp module fuse then reconnecting the battery to see if it would eliminate the call but no, the lights still came on.

So I decided to try to narrow down a command call path by checking different configs of plugging in the computers on the F42 circuit.
Hypothesis: if replacing the FEM did not fix the problem, then something else must be commanding the computers to complete the lighting circuit. So if I isolate power to the computers then I should be able to narrow down the problem circuit.
Test: disconnect the battery. Disconnect the DDM, FEM, REM, then reconnect them one at a time, and reconnect the battery checking for the interior switch illumination to come on.
Results:
FEM only= lights on
REM only= lights on
DDM only= no lights
FEM+DDM= lights on
REM+DDM= lights on
Conclusion: so I only know that the DDM isn't the problem. Whatever the trigger is, it commands both the REM and the FEM to activate all interior illumination.
What in the world do I do?

 

Try a hard boot by disconnecting the negative terminal of the battery for a good 15 minutes, and then reconnected the battery. Also, perhaps the main computer program somehow became corrupted and needs to be reprogrammed? Can the car still operate and run normally with the FEM disconnected? Of course, there would be the issue with the loss of dashboard illumination during night driving, but maybe something can be improvised. One could also leave a trickle charger on the battery when the car is not in use, but with a 2.5A quiescent current draw, you sure wouldn't want to park the vehicle anywhere for too long.

 

Did you check all of the door switches and trunk/boot switch? The door switch in most cars just grounds out an turns on lights. I checked what lights go on when you open a door. Answer: Quite a lot. Worth testing. I think the Trunk switch is part of the open/soft close motor assembly.

While thinking about it, I realize that the "unlock" function of the key fob also turns on interior lights and approach lights under side mirrors. Does your fob lock/unlock as designed?

I have LED replacement lights all over the interior as well as front parking and license plate lights.. they all glow when car is off and powered down. I planned to add small resistors to them,, but the draw is minimal. In the winter I use a float trickle charger in really cold weather, just for piece of mind, but I haven't seen the amperage drain you are experiencing.

Wouldn't hurt to check all the ground studs for cleanliness. Just don't torque the nuts back on more than 6.5 lb.-ft. / 9 Nm, which is really just "snug." Ask me how I know. They break off really easy. Trust me on this one.

Best of luck and keep us posted. Really curious issue and hope you find root cause soon!

 

Thank you for your suggestions, I had some thoughts along similar lines so:
I ​​​​​have left the car disconnected from DC ground for 12-24hrs a few times in all of this work.
If a computer is corrupted it won't be the FEM as I have tried swapping it out, though I have heard of bad "blocs" or some code language that another module might store and give to the new module??
I believe the FEM is necessary for running as it is on a circuit with engine run/start in the fuse list, but as the issue would persist with only the REM plugged in, it wouldn't help me if the car did work without the FEM.
I have the right charger but I want this to be my daily like my last xj (that I still own and love but was totalled and is now a parts car) and I work ten hour shifts so it would be dead every day.

 

Thank you very much for your brainstorming and checking!! I have been on some similar roads but you bring up some interesting points so:

I'm not totally sure what you mean about checking the doors/trunk switches but I have operated all of them whilst the actual body panel was open (iow false closing the doors to perform lock and security mode) and even in normal function everything is... Normal. That being said I did replace the trunk button, though I don't think the problem began at that point?

Everything involving the key works like a charm.

I have replaced some exterior w5w's with LEDs in both my X350s but haven't seen them glow! I know certain triggers keep different light circuits active for quite some time, perhaps with LEDs that time gets skewed, but that's not my issue luckily!

I too have broken a ground stud on my other xj to my dismay and I have heard that a visual check alone shouldn't suffice but I have at least visually checked all the earths.

Update: while illegally driving my totaled yet visually and performancelly normal xjr today I noticed that the lights I'm having trouble with in my super v8 are the exact lights that cut on with the sidelights/lowbeams. So not the interior big bulbs but rather everything green or pronouncedly orange except the parking brake light, which has always clearly been on its own circuit. But I really thought I checked that circuit, I disconnected the switch behind the steering wheel and checked, and I pulled the auto lamp fuse and checked. But that seems too much a coincidence!

 

Whether your front parking lights glow at the same time when interior lights are weirdly glowing?

 

So I got ahold of the legit wiring diagrams and spent a few hours going over those. Deduced that an SCP command message might be persisting due to the master lighting switch (roof console) not functioning.
So I pulled the roof console from my xjr and popped it in the Super V8 with battery disconnected. Plugged in the battery and the led backlighting issue persists and the "new" master lighting switch didn't work AND when I removed the roof console I could smell electric smoke/heat.
So I don't think I smoked the master light switch button by cleaning it, but rather there is a short or over-power there.
Still can't find a link to that and the "backlight LED activate" command though in the diagrams, but I'm glad to have them at last!

 

Alright so, after a few more hours pouring over the wiring diagrams and more importantly going over the changes I had made and the recent discoveries, the paths for solution met at the overhead console.
So I hopped in my xjr to examine every detail of the overhead console receiver. The hand of God Himself guided me to consider that I had never looked from the passenger seat. So I hoisted myself above the center console and looked left inside the headliner and noticed, "oh there's a little harness that runs there, that's nice" and continued looking. The grounding pins looked invulnerable so I was losing hope that I would find a clue.
Hopped in the super v8 immediately and yeah, it looks the same, the pins were in great shape etc.
Then BAM, it hit me, "oh no! The mic I put in right there, it's super close to that new wiring harness! But I measured where it goes in accordance with the xjr! Well here goes nothing..."
So again I hoisted myself above the center console and WHAM! I didn't hit my head... Lol jk... I saw my mounting screw going right through the middle of the tiny harness. I just "had" to put a second screw in to make a stronger like-factory installation, I just "had" to point the mic slightly down at the driver for better sound pickup. And I just "had" to put a screw in the 1/4" space where a never-before-seen wiring harness is hot glued to the headliner and can't get out of the way.
So I pulled the screw out, took the stupid risk of plugging in the battery and voila! Everything is right as rain. Now to repair that little harness and get back to loving Jags.
Thank you everyone who read all this to try to help. I hope this can help someone somehow someday.