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power car headlamp with LED as home decoration lamp? Answered

Hello, everyone

I have this Audi A4 Lamp with LED DRL, I want to power the LED up at home as decoration.Opened the headlamp housing, and trace the wire, I found the led strip has 4 wires, and I don't know which is (+) which is (-), I did some internet search of 4 pin led strip, and most of the info was RGB led. I don't believe this Audi LED DRL has RGB. tried (+ + - -) (+ - - +) (- + + -) with no luck. 
any advice to power the LED up at home?

Thank you.


The LEDs will be designed to tun on 12V - what size battery did you test with?

Thank you, Kiteman
I did, but don't know which wire is which, I took apart the LED, hope this will help for wiring.


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It looks like that is set up as 2 series strings of LEDs. Probably broken down to 7 LEDs per string. As the flat flex cable indicates the 2 center contacts are probably your positive with the outer being negative.

Or they could be set up as 4 seprate strings of LEDs in series in which cases the entire flat flex cable is the positive leads and there is a common ground somewhere.

In Either case you should be able to take a 9V battery and start touching your leads to the battery terminal till you get things to light. If nothing lights off those 4 connections then look for a common ground somewhere else.

If this is metal I bet that is your negative.


A manual for the car should give you a wiring diagram - a good start. Your library may be able to help with the manual.