SwedeSpeed - Volvo Performance Forum banner

1 - 6 of 6 Posts

·
Registered
Joined
·
258 Posts
Discussion Starter · #1 ·
Hello all. I just plugged in LED bulbs (from 42 Draft Designs) for the rear plate light and I noticed tonight when the car is off the bulbs dim and don't go completely off. When the light switch is turned on they brighten as they should. I reversed the bulb but I think LED's have a polarity something-or-other so reversing them didn't work so they only go in one way. I re-installed the stock bulbs and they work as they should; meaning the light switch is off the bulbs are off, the light switch is on the bulbs are on. Any ideas?
 

·
Registered
Joined
·
1,100 Posts
So, I noticed something like this on my mother's XC70 with the small lights in the headlights. They run for as long as the computer system is active. It probably just some leakage current from all the semiconductors used in the car. LED's glow a little because they use the low power more efficiency. They should go out when the computer really powers down. I've never timed it, but it should be around 30 seconds, but may be a couple of minutes. CHeck it out. If I'm wrong, then time is something else entirely and I know nothing.
 

·
Registered
Joined
·
738 Posts
Nothing to worry about man. Titan has it right, leakage current from the computer. As he also said, LEDs are able to be powered much lower than the stock bulbs so you will see them turn on sooner (powerwise). Once the computer shuts down the lights should as well. I have LED lights in my Nissan Xterra and they remain dim for up to 5 mins with the vehicle turned off but then the dim lights also fad away.

The LEDs are not drawing anymore power then the old bulbs, and they are not installed backwards. One thing you can do is install a resistor inline but honestly, more trouble then its worth.
 

·
Registered
Joined
·
434 Posts
If it bothers you, the way to fix this is to solder a resistor across the negative and positive leads. Not something that would concern me with license plate bulbs, but I did this with a custom led board I made for the dome light on a different car I used to have. It annoyed me having the dome light barely on while the door was shut and the engine on. Most if not all vehicles will cause the led to barely illuminate if not fixed with the resistor. As Loki said, the power it is drawing is certainly no concern and they do turn off completely after a few minutes.
 

·
Registered
Joined
·
258 Posts
Discussion Starter · #6 ·
Thanks Titan Joe and to the rest of the gang!
 
1 - 6 of 6 Posts
Top