Dear all:
I unfortunately searched and posted on the wrong forum (X150) and was re-directed to here. Hoping someone has some insight. My license plate lights are out on my 2003 XKR. I have tested bulbs - OK; checked the wiring through the hinge and trunk lid - OK; checked the 5 amp fuse in the trunk - OK, and the associated tail light works.
I see in the X150 forum there are several posts about doing a hard reset (disconnect batteries and short terminals) to reset the auxilliary board which apparently powers the license plate lights. I have tried this, but no joy. The X150 furum says the aux board is behind the middle panel of the rear seats - well my rear seat is solid and I don't know if the X100 uses the same arrangement of auxilliary board or not?

Anyway, does anyone have suggestions? Note also the trunk button on the trunk has never worked while I owned the car - but no big deal as the remote works the release and the button on the dash also works. If no other suggestions, I am thinking of simply hard wiring the license plate lights to a tail light circuit. Does anyone see a potential issue with that approach?
Thanks for any help and suggestions
N

 

Have you cleaned and burnished the license plate light bulb sockets?

 

Hi
Thank you for the reply. Yes, I have checked and cleaned the conections and also checked for a voltage in the wires going to the bulb holder using a multi-meter. I can find no voltage in the lines, and no connection to ground on either of the wires feeding the bulb holder.

N

 

They are powered from the same fuse as the RH tail lamps, although they do route separately via the Security & Locking Module for bulb fail monitoring. No message in the dash?

Odd you have neither power nor ground - there is a connector (BL1) under the trunk lid liner which may have an issue? The external trunk release wiring also inhabits that same connector.

 

Hi
I have loosened the trunk liner and located BL1 - no voltage on any of the 4 pins. I have inspected the cable especially in the prtector around the trunk hinge - no sign of any breaks etc. No messages at the dash. Also, fuse is good adn RH tail light is working
N

 

From what you describe, I think it can only be the live feed cable/harness at the hinge. It may appear Okay but you need to check it's continuity to be sure (From Fuse to Bulb Holder).

 

OK, if we go upstream a little further there is connector BB1, which also passes through for number plate lamps and trunk release.

According to the EG, this one is located 'above RH wheel arch', so in that general area.

Is the high-mount stop lamp working OK?

 

PKWise and michaelh
Thanks for your helpful input - I am 99 percent sure its not the cable at the hinge. I took apart the protector and the plastic cable protector. The cables inside are intact with no sign of chaffe or damage. I have had a look for BB1 above the wheel arch - that's tricky. The protected cable enters the body into the cavity where the fuel tank seems to be and appears again (still in protective platic conduit) down below, just in front of the battery. I can feel a cable connector up aroud the tank, but the trunk cables do not appear to go in that direction. I don't have a circuit diagram, but it sounds like these cables go to the security module? any idea where that is located? If I could find that I can better test continuity. However, I am fearing a bad board ....if its the same system as the XK150, then there is an auxilliary board that has given issues. Do you know if the XK100s have an auxilliary board and if so, where it is located?

 

Hi,
You can download a copy of the Electrical Guide from member Gus' site of everything here:
http://www.jagrepair.com/images/Auto.../jagxk2003.pdf

Section 9.3 for the rear exterior lighting.

The circuit for the number plate lamps does route via the security module (it's inside the trunk fusebox), so there might be an issue there, but that wouldn't explain the missing ground.

The wiring can break internally from the continual flexing without any visible symptoms. Continuity checks are the way to go, as PKWise suggests.

 

Problem solved thanks to the wiring diagram. I noticed that everything that shares BB1 was having an issue - so went on the search for BB1 which as the wiring diagram notes is in the trunk above the RH wheel arch. A bit of hair pulling to get back there with minimal disturbance to the lining, but after a few minutes of feeling around, I found BB1 connector, and it came apart in my hand. I am not sure if someone had been back in there for something previously, but it seemed like it had not been snapped together fully. Checked it, reconnected it - Bingo! license plate lights, and trunk lid latch/push button now work as advertised.

Thanks again for yuor help and guidance - I can now drive the rural Alabama roads at night without fear of another "courtessy stop" which started this hunt in the first place!

 

Well done....

 

Having the same problem with my XK8.
Checked wiring clamped to the hinge, and sure enough others had been in there doing a half hearted repair.
Following through on the previous posts here I quickly found two broken wires.
Repaired the wires by lengthening the broken wires and now we have Number plate lights working.
As a side issue how do you remove the globes from their plug after removing the lens?

 

Wear nitrile gloves. Give you just enough grip.

 

After noticing my trunk release button wasn't working and going to the first location of failure (wires at the hinge) noticed one severed and one frayed wire...spliced and shrink wrapped, all good. But, then I got to thinking...shouldn't the XKR button be RED not green

 

This Forum rocks!!!!!!