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Recently replaced the dome light in my Pure with a white led I found on eBay. Major improvement in cabin illumination and for $1.


At night, you can see the led bulb is still on. Very faint but there must be a trickle current coming through. I inspected the switch in place and found nothing wrong. I didn't disconnect it and take it to my work bench.


This was not noticeable with the stock bulb and I'm thinking there is just enough current getting through to fire the led.



I doubt if this power drain is a big deal but it does have me wondering.
 

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That circuit is controlled by a timer circuit to prevent a dead battery, and in the 'off' state there is not enough current to fire a lamp, but there is for an LED.


These circuits give feedback to the ECM for bulb status alerts.


Put the bulb back, the car was engineered in the time of LED's but was designed for tungsten just about everywhere.


SR
 

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Recently replaced the dome light in my Pure with a white led I found on eBay. Major improvement in cabin illumination and for $1.


At night, you can see the led bulb is still on. Very faint but there must be a trickle current coming through. I inspected the switch in place and found nothing wrong. I didn't disconnect it and take it to my work bench.


This was not noticeable with the stock bulb and I'm thinking there is just enough current getting through to fire the led.



I doubt if this power drain is a big deal but it does have me wondering.
I have LED's in all of my smart cars dome lights. I had the same issue with the first LED that I installed. You just need a higher quality LED and it will not stay on like that.
 

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I am not an expert, but I encountered the same issue before. So what I've learned is that circuit is controlled by a timer circuit to prevent a dead battery, and in the 'off' state, there is not enough current to fire a lamp, but there is for an LED. This is also why I switched to smart strip lights. Therefore, these circuits give feedback to the ECM for bulb status alerts. So if you are looking for a solution - put the bulb back and consider that the car was engineered in the time of LEDs.
 

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If you have a 451, the dome lights have some leakage current, about 20mA if I remember correctly. It’s not enough to light a an incandescent bulb, but will light an LED bulb dimly unless you use the switch in the light to turn it completely off.
 

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I found a solution to this!

If you spend a dollar or two more you can buy LEDs that have resistors in them. The resistors make it so that you're going to need more than the leakage current to illuminate the LEDs. These are sometimes called CANBUS LEDs.

My 451 has had a CANBUS LED dome light since 2014 and when the door is closed it is off. :)

On another note, these are the LEDs to use if you want to convert your exterior lighting to LED.
 
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Miss M,

You are 100% correct. LEDs with resistors will stop the glow, but won’t stop the current drain. It will still put a small load on the battery, but the LED to be able to see it.

If anyone is chasing parasitic battery drain, the dome light is one of the culprits
 
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