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B5 LED taillight bulb issue?

1.1K views 5 replies 3 participants last post by  Tomvw  
#1 ·
I recently got Lamin-x vinyls for a set of euro tails I got from a member, not knowing how dark they'd be I figured I'd get some LED tail & turn signal bulbs to avoid getting pulled over. The bulbs went in without issue and worked good when I tested them on the bench but once plugged in to the car I ran into an issue...When the key is on the third brake light is partially lit but dim and the remote start also aborts because it's seeing a brake input. The bulbs seem to work ok otherwise but I put the originals back in for the time being. I searched and didn't see any posts with the same issue & just wondering if any of you guys have ran into the same problem and maybe a solution?
 
#2 ·
LED bulbs and incandescent bulbs have very different electrical characteristics since an LED is a diode and an incandescent bulb is basically just a resistor. Is it possible you put the bulbs in backwards? A resistor operates the same in either direction but a diode operates differently when the ends are +/- vs -/+.
 
#3 ·
While the brake lights are not on, they operate as a ground for the CC system; standard LEDs do not provide a satisfactory ground.
This causes standard LEDs to partly light, and can provide a signal to other circuits. To overcome this you can fit an incandescent bulb or suitable resistor in the circuit.