[SphunaR]

Hi guys!
I have i30 GD bussiness with "normal" lamps.
I replaced lamps to new one LED.
It's work, but... when lights are off and i'm pressing brake pedal, everything is lighting:



but it should be only  "brake/stop":




So what's wrong?

[buff]

Hi I have replaced my Brake, Tail and indicators on my PD I30 from standard filament lamps to LED lamps and found a similar issue due to the way LEDs are managing the power supplied to them. When you apply the Brakes the Tail lights also come on.

If you Give me awhile (As I'm still having breakfast) I'll check how I inserted a Diode into the circuit and fixed the issue for me.

[buff]

Right breakfast finished and have some happy snaps that should help.
The modification I used is based on the main brake/tail lamp on my I30 is a duel filament P21/5W lamp.

First one shows the location behind main brake/tail light with the cable grommet (Plus the replacement LED lamps I have used)
Second one shows behind the grommet where I cut and soldered in a 3amp 40V Diode on the original wiring Tail Light feed (Pink cable) to prevent power going to the Tail Light in the other lenses.

This has now fixed the issue of all Brake and Tail lights coming on when you press the Brake peddle for me.

Just remember the Diode only work in one direction so if you do put them in and no power is getting to the lights you most likely have put the Diode in backwards.
Just a side note make sure you check your cables with a multi meter or test light to confirm its the correct cable for your model I30, as mine is a PD model and may differ in colour coding.

Hope this helps

[CraigB]

@SphunaR Have you replaced any other bulbs ( indicator - reverse)  within the factory LED tail lights when you upgraded to them?

The factory LED’s should be a direct plug & play which is why I’m asking if other bulbs were changed also.

[SphunaR]

Right breakfast finished and have some happy snaps that should help.
The modification I used is based on the main brake/tail lamp on my I30 is a duel filament P21/5W lamp.

Hope this helps

Thank you very much! 
I'll try it.
One more quetion: should I do it only on one side / one lamp?

Cables in my lamp:


So probably pink -> brake signal.

@SphunaR Have you replaced any other bulbs ( indicator - reverse)  within the factory LED tail lights when you upgraded to them?

The factory LED’s should be a direct plug & play which is why I’m asking if other bulbs were changed also.

No. I had standard bulbs for indicator and reverse before and after upgrade.
One of my collegue have the same issue. And i know another person, with the same car and everything works perfectly, without any changes.

[buff]

You will need to install a diode on both sides of the vehicle.
Hope it helps.

[SphunaR]

You will need to install a diode on both sides of the vehicle.
Hope it helps.

First test failed.
I have the same cables. PINK - sidelights/parking lights, GREEN - stop lights
So I 've installed diode on left left lamp in pink cable, but wuthout any effect. Sidelights are lighting when I press breake pedal.
What's strange: when I'm pressing breake pedal I don't have power on PINK cable...

Diode is bad? Or it will be work only when I install second diode on second side? Or something else?
Any suggestion? 

[The Gonz]

I don't understand what the diode is meant to achieve. LEDs are diodes, and the original incandescent lamps don't need diodes, so 'flow correction' is unlikely by adding them.

Where some cars do have trouble is with the greatly reduced current draw. Some using CANBUS logic sense too little and behave as if there is a blown bulb, for which the LEDs are accompanied by (typically) 6 Ohm 5W resistors in parallel.

When the wrong lights start to misbehave, it's usually a poor earth creating a divergent circuit.