Hello. I have a 2014 Jaguar XK Coupe with 40k miles. I have an issue with the courtesy lights (center dome light and footwell lights) not turning off when I click the center dome light button. I just had the car detailed (including engine bay) and only noticed this issue afterwards so likely related.

The lights stay on even with the doors closed and the car running. I have an Autel Scanner and checked the live data for the sensors for the doors, hood, and trunk and all are working properly. No messages on the dash for anything being opened. I checked the little dial that controls the illumination. The right and left dome light turn on and off fine. If I get out of the car and lock it until the mirrors fold in, the lights will turn off after several minutes, but not as quickly as it should. After the light went off and with the car locked, I reached through the window and pressed the center dome light button and the all the courtesy lights came on. Pressing it again, and they still stay on, so the button at least works to turn them on.

I took the dome light down to check the wires and it looks fine. I disconnected the connector and turned the car on and the footwell lights still came on with everything closed. Anyone have any ideas on what else to check? I'm stumped.

 

Try pushing the other two light switches.

 

@Cee Jay beat me to it. When in doubt, . You can find Owners Handbooks for the 4.2L and 5.OL models in the Stickies.

 

Interesting. Never heard of this one.
I catch your meaning about “related to the detailing”. I wonder, was the battery depleted? Please confirm the actual reading.
Have you actually opened and closed each door and the boot? I agree, this behavior does smell like an open door even though your codes show successfully.

 

Yes, I checked the other 2 buttons. They work fine.

Battery wasn't depleted, but it is weak. Cranking amps are still OK and did not have to jump it. I'm getting a reading of 12.3 volts right now, with the car off &interior lights on. I'm putting it on a charger now, to see if that helps. I did also try unhooking the battery for 10 minutes to see if it'd reset and didn't work. I've closed all the doors, hood and trunk and manually checked each lock as well one at a time. I just brought it my mechanic today and he basically checked the same things I did, but relubed all the latches and cleaned up the connections for the dome light and no dice.

 

I charged up the battery and no help. Does the dome light actually control the courtesy lights to turn off automatically or is that done through a control module? When I disconnect the entire dome light, my footwell lights are still on while the car is running, so if it's the circuit in the dome light that tells the car to turn them off, then maybe it is the problem. Otherwise I guess I have a wiring or short issue somewhere.

 

I just had the auto electrician go through the car. There is some intermittent codes coming through for the AUX junction box that come back after erasing. His idea is that the weak battery caused the computer in there to short out. Since the detailers would have the doors open, and be moving seats/draining already the battery. If you then go to start it after the battery is drained, it can cause damage to modules. Sounds plausible, but looking expensive as I only see 2 for sale and they are >$700.

 

Define "weak". The workshop manual is clear: 12.5v implies a charge or a new battery is needed.

 

Not sure what year your car is, there is quite a lot of info in the stickies thread electrical schematic manuals - page 59 - might be worth looking at them.:

 

This is the exact diagram that auto electrician went off of to say it was the Aux Junction box. He doesn't do repairs so I brought it to a Jaguar specialist that is able to program a replacement box in case that was the problem. First he said to replace the overhead dome light, but when I asked him if it was that then why do the footwell lights stay on if I disconnect the dome light entirely. He said he didn't realize the footwell lights were still on and then said to replace the central junction fuse box. Since he was all over the place, I just brought it to the dealer.

The dealer called me yesterday and also said to replace the overhead dome light and I again mentioned the footwell lights staying on when it's unplugged (even told them this upfront), and now they are saying they want to drop the headliner to check for more shorts and more $$$ in Diag time. I asked them to rule out the Aux box first and now he's having the foreman call me later today. What a pain in the ***...