On my 2012 XJL Portfolio the passenger side tail light decided to stop working recently. Currently the running light flashes on for an instant when the headlights are turned on and the brake light does not work at all. All other lights on the assembly are currently working (turn, reverse, and the top corner light). I have already removed the light and checked the connector and everything including the harness looks to be fine. If any one has any ides on what this could be or a wiring schematic so I could check it with a test light I would greatly appreciate it!

1bad55chevy, remove your tail light and put it on a bench. If you look at the plug, you should see small numbers imprinted into the plastic, Worst case, you will see numbers at the ends of the pins (ie, 1, 5, 6, and 10). These are referencing the pin numbers that I am mention below.

Using a small 12V battery (can even be a set of 8 AA batteries wired in series), add some wires coming off of the battery with a red wire to the + terminal and a black wire on the - terminal. Taking the headlight, touch the red lead to pin 1 and the black lead to pin 5 (at the same time). Did the brake light light? If yes, then your problem lies with either the junction box or the gray/violet wire running back to the tail light. If no, then your problem is inside the tail light and odds are, you will end up needing a new tail light since I believe these are not repairable without significant work and dismantling.

As for your running lights. First things first, do the running lights on your headlights work? If no, then check fuse F24 in the central junction box. If in doubt, replace the fuse (5 amp mini fuse). If the rear running lights still do not work, take that battery again and connect the red wire to pin 4 and the black wire to Pin 5. Do the running lights come on. If yes, then you are looking at a failed violetgreen wire between where it splits off from the front headlight and the rear tail light. If no, then this tells me that you have a bad tail light.

If you are suspecting a failed wire, then I would recommend getting your hands on a device known as a "cable chaser". these can be had on e-bay for like $40. These are normally used for tracking down telephone lines and CAT5 cables in big networks, but they work on cars really well. What you are going to do is connect the cable chaser to the car plug (either Pin 1 or Pin 4, based on what you found above) and then using the associated wand, start following the cable back to the fuse box. What you will find is as you start at the plug, the cable chaser wand will give you its tone. Once you go past the bad spot in the wire, the tone will stop. From there, you can inspect the wiring to find out why it is failed. In a lot of cases, you shouldn't have to remove the trim of the car as you simply need to be within a few inches of the wire to pick up the tone (may need to turn up the sensitivity though).

So the tail light looks to be the issue. I am still getting the same issues on the bench as on the car running light and brake light flash on for an instant then turn off. As for the wiring this is what i found out
1. Brake light
2. Reverse light
3. Blinker
4. Running light
5. Negative
6. Rear fog

now i need a tail light.. I refuse to pay $575 on Ebay when I can get a new one for $705 from Jag. Maybe i can find the new style ones cheaper or for the same price...

https://parts.jaguarpalmbeach.com/a/Jaguar_2012_XJ-L-Portfolio/_56655_6019645/TAIL-LAMPS-REAR-LAMPS/4726645.html

1bad55chevy, hopefully what I gave you helped you out. Sucks that you have to get a new tail light. But, at the same time, chasing down a wiring problem can have its own head aches. Atleast the repair will be fairly easy.

On a side note, you can get a new one through Jaguarparts.com for $564 plus any S&H. This appears to be a dealership out of San Juan Texas. Then you always have Guadin Jaguar who is a sponsor here and has helped out a lot of members here (I have personally used them and had a good experience).

Gaudin has it for 540.74 plus shipping. They do a great job. https://www.jlroriginalparts.com/oem...embly-c2d51413

Thermo,

your reply helped me ID the colors on the wires. I couldn't find the pin numbers you provided since the ones on the connector were different. I wish i would have known about that site earlier since i already purchased a black tinted light off ebay for $330 that came with a 30 day warranty.

Hopefully i can throw this on the car and i will be done with repairs for a little while.. The month of August alone has been over $7k in repairs on this car (lucky for me my extended warranty has covered almost 90% of these repairs). If it wasnt for the extended warranty i would have crushed and burned this car being that its taken over $15k in repairs since getting it in September 2017.

Hopefully you don't have to replace the front lights. They are $2k each (for the steerable ones). Dump that car before the extended warranty is up, needless to say!

I don't want to get rid of the car now that everything is fixed! In the past year this is what has been done to the car;

1. water pump (twice since replacement failed 1 week after being installed)
2. thermostat
3. oil pan gasket
4. upper control arms
5. front pads and rotors
6. all lower control arm bushings
7. sway bar bushings
8. PS pump
9. front passenger side strut
10. rear tail light
11. B-pillar interior panel recovered
12. both rear lower control arms replaced due to loose ball joints
13. carfax showed the ECU had been replaced a month before purchase

accessories added
1. powder coating of factory wheels
2. replaced ALL mid/bass speakers
3. new tires

The car is a 2012 and only had 29k miles on it and seemed to be very clean and well maintained. Now a year later the car has 50k on the clock and runs like a clock but the issue has been the suspension. Now that the majority of the suspension has been replaced I am not sure if I really want to get rid of it!

That list looks an awful lot like an oil change gone bad. And also the very reason I NEVER take an out of warranty car to a *********** for any reason.

Huh? What is so bad about a (add S and remove D) from Dealership?