Volkswagen Passat Forum banner
1 - 6 of 6 Posts

·
Registered
Joined
·
37 Posts
Discussion Starter · #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?
 

·
Registered
Joined
·
2,001 Posts
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 -/+.
 

·
I Know Stuff
Joined
·
10,579 Posts
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.
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #4 ·
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 -/+.
I had thought of this because I've ran into a non working led that was backwards before but the bulbs have one nub? higher up on the base so when you push it in and rotate it can only go in smooth the one way
 

·
Registered
Joined
·
37 Posts
Discussion Starter · #5 ·
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.
I didn't even think about trying to wire an incandescent bulb in with it to fix it. I have tons of bulb sockets around so I'm gonna try to take care of it this weekend. Thanks!
 
1 - 6 of 6 Posts
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top