AuthorTopic: Are LED bulbs (brakes/indicators, etc) road legal? Do they need extra resistors?  (Read 4515 times)

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Offline auf_wiedersehen_pet

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Are LED bulbs for brake lights & indicators road legal? Do they need extra resistors?
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Offline maggers

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I seem to remember that the official line is that if you fit a complete LED lamp they are legal, however if you fit an LED bulb to a lamp designed to use normal bulbs that's a no-no. ;)
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Offline Rossko

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Are LED bulbs for brake lights & indicators road legal? Do they need extra resistors?

Yes and No.

All LEDs require a series resistor to limit the running current.  This is usually built in and isn't what is normally meant when describing an automotive LED package as having a 'resistor'.

LED replacements for indicators will almost always need to have power-wasting parallel resistors to take enough current to fool the flasher unit that a regular bulb is in use, else it won't flash properly.
LED replacements for other bulbs may also need parallel resistors to dump enough current to fool any bulb-fail detection circuits that all is well.

Legal situation is unclear.  The UK laws don't mention LEDs at all, but specify bulbs of whatever wattage.   So in theory retrofitting a car with LED mandatory lights is illegal.   Many of course do pass MoTs with these units fitted.   A consideration though is that LED units tend to have 'beam' type pattern ; when used with lenses designed for real bulbs the viewing angles will be wrong.  A sharp-eyed traffic cop or MoT tester could just pick this up.
New cars are type-approved as a whole item, including any LED lamps factory fitted, so they don't have to comply with the older laws.
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Offline MaxMarshall

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I seem to remember that the official line is that if you fit a complete led lighting they are legal, however if you fit an LED bulb to a lamp designed to use normal bulbs that's a no-no. ;)
There is plenty of talks about these bulbs are real or not.. I have seen many individuals using them so they must be legal
« Last Edit: July 30, 2013, 17:27:49 by MaxMarshall »

Offline trecfive

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I seem to remember that the official line is that if you fit a complete LED lamp they are legal, however if you fit an LED bulb to a lamp designed to use normal bulbs that's a no-no. ;)
There is plenty of talks about these bulbs are real or not.. I have seen many individuals using them so they must be legal
I have seen many individuals smoking dope, thats not legal, but they do it.
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2. Range Rover Classic 300tdi SE Auto Softdash, apparently very rare.