I have been upgrading the lighting inside my car to LED and I have noticed a rather odd occurrence. I noticed last night (first time I have driven the car at night with the new lights) that the four map lights (2 up front, 2 in the back) glow slightly when the headlights are turned on. It isn't anything that is lighting up the interior of the car. But the map lights have a white glow to them. They will also glow after you get out of the car and lock the vehicle.

Anyone else notice this when they upgraded to LED lighting? I think I know the fix to this. I just don't want to start cutting into things for something this simple. I know it would be nothing more than installing say a 100 ohm resistor into the circuit to act as a drain. Is there another fix?

It isn't a particular LED light that I am using that has this issue as I have 2 different types of LED bulbs in these locations. Both are doing the same thing. One style is a 9 SMD 5050 setup. The other is a 24 SMD array stick.

I am doing some playing and there will be a big write up on a bunch of different LED bulbs and lots of useful information, but need to get more bulbs first. I should have around 8-9 different LED bulbs all based on a 194 bulb. I will be doing a big comparison based on power draw, amount of light, color of light, and direction of light. This will hopefully be something that is very useful. This will be coming in November when I get some time to do some playing.

 

I wonder if you have hit upon the cause of the "low Battery" issue that many pre 2013 XJ owners complained of hmmm.

 

XJsss, I am going to do some more looking into this once I get back from my business trip. So, we will see what happens. While I won't be able to get rid of the battery drain, I think I know how to make the lights not be lit dimly.

As for what is going on, I have a theory on this and would need to do some very deep looking into the diagrams to confirm this. What is happening is the computer is using a transistor to turn the lights on and off. So, the transistor is your on/off switch. Unfortunately, a small amount of current can "leak" through the transistor (we are talking on the milliamp scale, so a very small leak). But, because of the efficiency of diodes, even this very small current can be enough to cause them to glow. This isn't a problem if you have a standard bulb in the circuit because it requires a lot more current to cause the filament to get warm enough to emit light (or voltage for an incandescent bulb affects how bright it is and voltage is a function of current times resistance, to which the incandescent bulb has very little resistance compared to a diode).

But, like I mentioned in my original post, the lights will turn off once you lock the vehicle. With the engine running, this is not enough power to overload the alternator (not even close). So, I am really doubtful that this is the issue unless there was excessive leakage from a transistor leading to a higher current draw and if the car sat for say 5 days, then that could result in a dead battery.

Do not worry, I will get to the bottom of this.

 

I just picked up a beautiful XJL 2011 caviar with ivory interior, very low miles (my first jag by the way) anyways I just did the same upgrade and the reason for this is because leds only need a very low current to work and our dome lights have a very low current running threw them even when they are off.

This causes the leds to illuminate ,it's not enough current to do anything to the regular bulb but just enough for the led to illuminate

 

[QUOTE=Guy2k;1334850]I just picked up a beautiful XJL 2011 caviar with ivory interior, very low miles (my first jag by the way) anyways I just did the same upgrade and the reason for this is because leds only need a very low current to work and our dome lights have a very low current running threw them even when they are off.

This causes the leds to illuminate ,it's not enough current to do anything to the regular bulb but just enough for the led to illuminate..this is what my installer told me...

 

[QUOTE=Guy2k;1334854]

 

Interesting to hear this, about 4 years ago we were involved with installing a lot of ceiling lights in houses, we were fitting them with led lamps, the budget of the customer did not allow for top quality name brand lamps so he insisted we use lower quality foreign lamps.
We also noticed that on some there were very faint glowing emitted even when the lights were turned off, the electrician at the time mentioned something about very small currents making them glow. Probably similar to what you are describing here.

 

Hello,
What LED did you used and where can I purchase them. I want to change them as well in front and rear and if it's possible at feet. Can anyone provide a link. thank you

 

cicirrigi, you may want to wait a little bit. I am looking to do my own side by side comparison of a bunch of different style LEDs that fit in the 194 bulb base (which is what our cars mainly use). Keep in mind that LED lighting is very directional. So, in the case of say the overhead lights, the bulb base points front to back, not straight down. So, if you get an LED that points out the top of the bulb, it will light up the car very poorly. Where, if you get an LED bulb that shines out to the side and not out the top, it will light up the interior of the car very nicely. On the flip side, the license plate bulb bases point at the license plate. Therefore the bulbs that would work very poorly in the interior, work great there and the ones that work great in the interior would work horribly for the license plate.

Currently, I am using the following for the license plate:
10 X Car White T10 LED 9smd Side Wedge Light Bulb W5W 194 168 2825 501 192 158

I am using these for the interior:
2pcs T10 W5W 194 168 6W LED No Error COB Canbus Side Lamp Wedge Light Bulb White | eBay

On a side note, from personal experience in playing with electronics, I have found that the multiple SMD bulbs (ie, 5050 SMD, 5630 SMD, etc) do not tend to last too long as the solder joints are very small and the LED does get warm enough that over time the solder joint in short will corrode and/or wither away, resulting in an open circuit, leading to the bulb not working. So, the ones that I am using for my license plate at the moment is more an experiment to see if the quality has improved with time. This is why I am using a completely different style on the interior as I have found these tend to have a much longer life and also shed much more light. The only down side I have found is the interior lights have a very faint glow when you have the lights on at night. But, this is a characteristic of how LEDs function and how Jaguar wires up these lights. They are not bright enough to be distracting while driving, but it can lead to questions. I actually find it somewhat beneficial as you know exactly where the map/touch lights are as they are the only ones that light up like that. I will be coming up with a fix for this most likely once I can get back home.

If you have more questions, let me know. I will pass on everything that I know. But, I have like 10 different kinds of LED lights waiting for me to do a side by side comparison that I plan on posting here for all to see.

 

Thermo, Thank you very much for your elaborate answer.What tool do I need to remove the light covers? Do the bulbs underneath the mirror can be changed and are they the same model as the interior ones? I think I will wait if you say you'll make a comparison.Anyway I was not in a rush. Is just that the current lights of the car are old fashioned. There are two things that I cannot stand..the lights and my navigation menu.I have the first model of navi (2010) and the interface is very ugly. I have tried to find a solution to update it but no one has any precise information regarding this. Cheers

 

The interior lights are accessed using a small flat blade screw driver. The rear lights if you look at them have 2 small rectangular holes on the leading edge of the clear plastic. You can stick the screw driver in there and release the tab that is inside on each side. This will allow the clear plastic to slide out and then allow the whole light assembly to come down. From there, you can twist out the two light bases and swap the bulbs. Install is simply holding the light housing up to the ceiling and then sliding the clear plastic back into place.

The front light, you simply need to slide the screw driver between the plastic surround and the ceiling liner on the side nearest the sunroof. From there you can pull the light assembly straight down. This will cause it to rotate slightly at the side nearest the windshield. ONce you get it rotated, you can release it and then access the light bulbs by giving the bulb bases a slight twist.

As for accessing the mirror lights, I have not swapped those yet. So, I cannot speak as to how to access those bulbs. I remember reading about it and it didn't seem too difficult.