LED bulbs in interior lights question - SORTED THANK YOU

[LeylandVCDS]

Quick question please -

Nearly 4 years ago I swapped out the interior roof bulbs to LED and have only just found out that they permanently glow very, very dimly when the lights are "off". This is both whilst driving, and also whilst the car is locked and parked up too. They are so dim whilst "off" that it's hardly noticable, and it was only a back seat passenger who noticed it last night whilst we were out Northern Lights hunting! When the doors are on, they work brightly as expected, no issues. Car is a 64 plate Leon SE Technology TDI.

Anyone else noticed this? And would different LEDs solve this issue?

And no, we didn't see the Northern Lights!

Thanks in advance

 

[RADIOTWO]

Quick question please -

Nearly 4 years ago I swapped out the interior roof bulbs to LED and have only just found out that they permanently glow very, very dimly when the lights are "off". This is both whilst driving, and also whilst the car is locked and parked up too. They are so dim whilst "off" that it's hardly noticable, and it was only a back seat passenger who noticed it last night whilst we were out Northern Lights hunting! When the doors are on, they work brightly as expected, no issues. Car is a 64 plate Leon SE Technology TDI.

Anyone else noticed this? And would different LEDs solve this issue?

And no, we didn't see the Northern Lights!

Thanks in advance

I think I come across this some years ago (on a different make) but I wonder if it has a delay on the lamp so the tight
stays on for a time after you shut the door, and then goes off, but with LED's you get them staying on because of the
very low current draw, where a standard halogen lamp shuts the circuit down and works as it should.

first thing replace the old lamp and see if it works as it should then its the LED, but if it is the led then put a resistor to
make it it think it is drawing the full current

 

[LeylandVCDS]

I think I come across this some years ago (on a different make) but I wonder if it has a delay on the lamp so the tight
stays on for a time after you shut the door, and then goes off, but with LED's you get them staying on because of the
very low current draw, where a standard halogen lamp shuts the circuit down and works as it should.

first thing replace the old lamp and see if it works as it should then its the LED, but if it is the led then put a resistor to
make it it think it is drawing the full current

Thanks for the reply - I should say that all the roof interior lights are the same - the two W5W map lights and festoon in the front light unit, and the two festoons in the rear light unit. All the bulbs glow at the same dim level, but still all work perfectly brightly when the doors are open or the lights switched on.
It's nothing to do with the courtesy light delay on the car - when the doors are shut with ignition off, the lights stay on for a few seconds then dim to almost off - normal bulbs go completely out, but the LEDs are staying on very dim as described above permanently. They are still on very dim in the morning after the car has been locked up all night
And even with the switch in the light unit in the off position, the LEDs are still glowing dimly

 

[RADIOTWO]

Thanks for the reply - I should say that all the roof interior lights are the same - the two W5W map lights and festoon in the front light unit, and the two festoons in the rear light unit. All the bulbs glow at the same dim level, but still all work perfectly brightly when the doors are open or the lights switched on.
It's nothing to do with the courtesy light delay on the car - when the doors are shut with ignition off, the lights stay on for a few seconds then dim to almost off - normal bulbs go completely out, but the LEDs are staying on very dim as described above permanently. They are still on very dim in the morning after the car has been locked up all night
And even with the switch in the light unit in the off position, the LEDs are still glowing dimly

I think you are missing the point ! because the LED's are not drawing the correct current then they are staying on (very dimly)
so you need to draw more current by putting a resistor

 

[LeylandVCDS]

I think you are missing the point ! because the LED's are not drawing the correct current then they are staying on (very dimly)
so you need to draw more current by putting a resistor

I would have thought that canbus friendly bulbs would already have resistors in the circuit

 

[RADIOTWO]

I would have thought that canbus friendly bulbs would already have resistors in the circuit

not to get it to the original wattage

 

[mjj4]

I wouldn't worry about it, I think it's something to do with the canbus system sending signals out to see if the bulb (when original) is open circuit or not to see if it's failed. You wouldn't see this but as the LED draws so little current and only needs ~2v to illuminate you have them on dimly lit permanently. Adding a bleed resistor will stop this but won't stop the current drain, you just won't be able to see it.

My R8 engine bay LED's are factory fit and they stay on permanently lit very very dimly 24/7. I don't drive the car over winter and leave it without starting for months during this time. Still fires up when it hears the grit lorries park up.

So if it doesn't annoy you, don't worry about it.

 

[LeylandVCDS]

Thanks for your replies = changed the bulbs to different LED COB Canbus ones, not only are they much brighter than the LEDs that were in, they now shut off completely too

Thanks again, much appreciated

 

[andylong]

Canbus led bulbs add circuitry to show a load where other units would. I'd be surprised if interior lamps were part of the canbus system. Maybe they are I dunno.
LEDs will glow at low currents because of the internal circuitry making the best of what little power is on the circuit where a filament bulb would draw some current but not enough to glow.