Skoda Octavia II - Rear High LED Problem

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Fri 2 Apr 2010 23:59
Skoda Octavia II - Rear High LED Problem - riemann

I have just purchased a '05 Skoda Octavia 1.9TDi.

I have noticed today that the Rear Centre Brake LED stays dimly lit even when the car is turned off and locked.

Its just 3 led's on each side of the line. 6 in total. When the brake pedal is pressed the whole line lights up as normal plus the 2 other brake lights.

I did wash the car today so maybe some water got in somehow.

I also rang the previous owner who said it happened to him twice and on both occasions it went away by itself (whilst he was on his way to have it looked at in a garage!)

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Thu 19 May 2011 11:06
Skoda Octavia II - Rear High LED Problem - Sarah17

Did this problem sort itself out for you, if so how long did it take? As I have just discovered the same issue, with my '54 Octavia. I cant get it in to the garage for another week, and I am concerned that my battery will die before then.

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Thu 19 May 2011 15:27
Skoda Octavia II - Rear High LED Problem - mickyh7


Location: Yorkshire,
United Kingdom
Thanked: 189 times

"
Hello.I've pasted this from else where.Its quite common.

If you've ever delved into electronics, you'll know what a capacitor is. Basically two large plates, pos and neg, with an insulator between. The basics are that this will let through some charge, but it stores most of the charge it recieves. I think.

Now, think about the cable between your two switches. It has three phase conductors. In any position of the two switches, at least one of the cores is always live, and at least one is always dead. When the lights are "off", they are directly connected to the dead core. Because the dead core is right next to a live core, the two act like a capacitor, and an amount of charge is allowed through onto the dead core. Thus some current will flow through the lamps to neutral.

The interesting part is how different types of light deal with this current. Because the current is so small, a 60 watt filament lamp will simply pass the charge over its filament with no noticeable glow or heat, since it takes significant energy to make it glow.
An LED requires so little current to run, that it may well glow slightly due to this current as it passes it over its semiconductor emitter.
The one which makes people panic is the energy saving lamp (CFL). Because there is no direct connection from live to neutral through the lamp, the CFL stores the charge until there is enough to pass through the lamp by way of an electron arc. This manifests itself visually as a slight flicker every 10 or so seconds. Nothing to worry about.

Edited by mickyh7 on 19/05/2011 at 15:29

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Thu 19 May 2011 17:16
Skoda Octavia II - Rear High LED Problem - Peter D

I do not know where you copied it from but If I were you I would put it back.

I laughed so much I spilt my coffee, the leakage between two adjacent cables is many orders of magnitude smaller that the current required to light an LED.

That is not the problem in the Skoda. Regards Peter

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Thu 19 May 2011 18:23
Skoda Octavia II - Rear High LED Problem - mickyh7

Its also happened to a chap on one of the Vauxhall forums,where he replaced the interior light with a festoon/LED !

Faraday's Law - 50Hz alternating field and all that ?

How else can it be explained ?

I'd be interested,as there are loads of cars with LED's on the road now.

Edited by mickyh7 on 19/05/2011 at 18:25

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Thu 19 May 2011 18:24
Skoda Octavia II - Rear High LED Problem - bathtub tom

It explains why my landing light flashes.

I've been wondering for years.

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Thu 19 May 2011 18:27
Skoda Octavia II - Rear High LED Problem - mickyh7

It explains why my landing light flashes.

I've been wondering for years.

Upstairs Hallway or Light Aeroplane ?

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Thu 19 May 2011 18:40
Skoda Octavia II - Rear High LED Problem - Peter D

What has 50 Hz got to do with car electrics. The Vauxall fault, depending on the year could be down to the auto fade not actually not turning off completely, I've changed a couple of those. Regards Peter

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Thu 19 May 2011 18:46
Skoda Octavia II - Rear High LED Problem - mickyh7

That would answer that then. And it makes sense.

The brake lights,I really don't know,just having a punt !

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Thu 19 May 2011 19:01
Skoda Octavia II - Rear High LED Problem - elekie&a/c doctor

Just change the brake light switch and the job is fixed.

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Thu 19 May 2011 18:58
Skoda Octavia II - Rear High LED Problem - Peter D

I've checked the CCT diagrams and the live feed is in fact the switch feed for the brake lights so there is no permanent feed to the light cluster. The high level light is fed of the rear near side brake light. What model is this car is this an estate. Regards Peter

Edited by Peter D on 19/05/2011 at 19:02

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Sun 25 Mar 2012 13:37
Skoda Octavia II - Rear High LED Problem - a_maqsoud
dear Peter
i am facing this issue , do you know what the solution for it , if the feed come from the rear near side brake light, what can i do to fix it.?
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Fri 30 Mar 2012 13:26
Skoda Octavia II - Rear High LED Problem - MrEckerslikefromRamsbottom

Capacitors? I wonder.. Are there any electronics within this light unit? I read of LED driver ICs to control the current and hence the intensity of the light. Never had one apart meself, but I can understand that a good quality unit may have such controls, so perhaps talk of a capacitor holding charge and leaking it to cause a dim glow may be valid! And as for the 50Hz idea? Well, many LED lights are run with pulsed current, often at 50Hz. Ever passed through a road junction at night and had the illusion that the little red or green men on the pedestrian lights formed a line of little glowing men as you blink and turn your head? That's because they aren't continuously lit, but pulsed, so a LED stop light with electronic driver would employ the same technique, methinks. Anyway, to find the problem....

Disconnect the feed wire from the dimly gowing LED cluster. Does this clear the problem?

Yes? Then get a meter on the wire and see what voltage is on there. Go back to the stop-light switch on the brake pedal.. Is that leaking current in some way? Perhaps an insulation problem (Which wouldn't cause a filament bulb to glow).

No? Then the fault is within the unit, so it won't cause your car battery to go flat. If it is a capacitor leaking charge, then the glow should fade away after a short time... Try drying the unit out with a hair dryer.

I want to get my hands on one of these now!

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