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LED Replacement lights

Posted: Wed Jul 08, 2009 3:32 pm
by Graham
Just a thread about replacing normal filament bulbs with LED "bulbs".

Upsides:
Longer life
Less power consumption
Less power

Downsides:
Not as bright???
LED's may go out one by one
expensive

I got bored so I decided to get a pair of 36-LED brake lights (T20 I think they were)

To be honest I can't really see a difference at all, If I have the bulb in the left side and the LED in the right side of the tail lights you cannot tell them apart from a distance. From up close there is a tiny difference, but nothing substantial.

I think I may stick with the standard globes.


Has anyone done this, have you noticed any positive or negative results?
I'm curious to know :P

Posted: Wed Jul 08, 2009 4:11 pm
by dumb&
On bigger lights such as the brake lights you may not see as big a difference.

When replacing stuff like parkers/license plate globes is where you'll see the biggest light difference, especially if using SMD LEDs as opposed to regular leds. SMD leds are a whole lot brighter.

Posted: Wed Jul 08, 2009 4:43 pm
by Bandit
I like the fact LEDs come on instantly and don't have to 'warm up' for that brief portion of a second like incandescent bulbs do.

The LED replacement units are probably as bright as globes, but it really depends on the angle you view them from and of course the diffusion inbuilt to the car's lenses. These are obviously set up for incandescent bulbs and do not always suit LEDs as they are a more focussed light source than the incandescent. This is why some LED brake/tail clusters now come with LEDs facing sideways, but they still aren't as good as bulbs yet.

There is also the other issue of the LEDs (particularly in indicators) not drawing enough current and the car thinks that the bulbs is blown, making the indicator flash faster. Resistors can be purchased to alleviate this problem,. although I am not sure where you'd actually put them inside the light assembly.

Posted: Wed Jul 08, 2009 5:13 pm
by SIR-VRX
The main advantage of the LEDs in automotive use is the speed of the illumination.

Also, you may want to be careful of LEDs as tail lights... (in your case your stop/tail is a 36-LED globe)

They send the ETACS ECU into a spin. The ETACS ECU is the main computer controlled system that does all the switching of pretty much everything in the car. It has a blown bulb detection circuit in it, and when the tail lights are made LEDs, the extremely low resistance of LEDs confuses it. It confuses it into thinking that there is a faulty speed sensor (who know why haha) and it disables the ASC and the cruise control.

Load resistors are available, at about $15 each. They do get warm and they are a decent size (bit bigger than an AA battery) so mounting them is difficult. They can also be used for the indicators, as the indicators also have the blown bulb detection, only by law their flash speed must increase instead.

Posted: Wed Jul 08, 2009 7:11 pm
by Dummer
SIR-VRX wrote:It has a blown bulb detection circuit in it, and when the tail lights are made LEDs, the extremely low resistance of LEDs confuses it.


LED replacement bulbs generally have a much higher resistance I thought...

Posted: Wed Jul 08, 2009 7:18 pm
by SIR-VRX
Ryan_C wrote:
SIR-VRX wrote:It has a blown bulb detection circuit in it, and when the tail lights are made LEDs, the extremely low resistance of LEDs confuses it.


LED replacement bulbs generally have a much higher resistance I thought...

Yes, when not illuminated they have an infinite resistance. It's when the current passes, they have pretty much nothing :wink:

Posted: Wed Jul 08, 2009 8:03 pm
by Dummer
Yes for a single LED that's true but when arranged in a circuit you need to limit the current, usually through resistors.

So the LED replacement bulb will have a higher resistance than a normal incandescent...

Posted: Wed Jul 08, 2009 8:14 pm
by SIR-VRX
Ryan_C wrote:Yes for a single LED that's true but when arranged in a circuit you need to limit the current, usually through resistors.

So the LED replacement bulb will have a higher resistance than a normal incandescent...

The ones I have aren't. Nor are any I've tested. A current limiting resistor is only a small ohm, an incandescent 20W bulb is a pretty high resistance. hence why the load resistors to replace them are so big and heavy

Posted: Wed Jul 08, 2009 8:41 pm
by Dummer
Nah you use a resistor anywhere upto a few hundred ohms depending on the current the LED takes and its voltage drop.

P=VI and V=IR

to which we get,

P=V^2/R

LED globes use less power than an incandescent yet you are still applying 12V to the socket, therefore the resistance has to be higher in the LED globe to account for the lower power consumption.

Load resistors have only a few ohms though so that they'll pull enough current to account for the lower power used by the LED globe. The reason they are big and heavy is because they'll be ceramic or aluminium encase for thermal dissipation.

Posted: Wed Jul 08, 2009 10:27 pm
by moltisanti
hey all,
i was looking into some LED's for parkers, and number plate lights, probly just the white ones. are there any problems with putting these in? mate said they can get hot or something, so thought i'd check.

also does any one know of a good brand of headlights? not HID just the bright white/blue style normal globes?

cheers

Posted: Wed Jul 08, 2009 10:46 pm
by dumb&
Philips Power2Night - will set you back about $120 from Autobarn for both high and low beams.

You can get em on the net a bit cheaper.

Posted: Thu Jul 09, 2009 9:19 am
by Graham
moltisanti wrote:hey all,
i was looking into some LED's for parkers, and number plate lights, probly just the white ones. are there any problems with putting these in? mate said they can get hot or something, so thought i'd check.

also does any one know of a good brand of headlights? not HID just the bright white/blue style normal globes?

cheers


LED's look alot better in the parkers, I had white globes but had some spare blue T10 LED's laying around so I threw those in parking lights/license plate holder. They do look pretty cool but are you can get in trouble for them (by the police)

They're fairly easy to put in, just reach in twist and pull out & switch globe and put it back in (It's a bit harder to put it back in than it is to take out though IMO)

I need to change mine back to white when I have the time, I just need another white SMD T10 bulb first.


Thanks everyone for the info aswell :)

Posted: Thu Jul 09, 2009 9:31 am
by Dummer
Dude don't risk a defect and/or fine for impersonating a police vehicle, ditch the blue parkers :lol: They scream "PLEASE BOOK ME"!!

moltisant, there are heaps of choices on eBay. Just for some white T10s (a.k.a. W5W globe) and you'll be right. They make less heat than a normal incadescent T10 bulb so dunno what mate your mate is talking about...

As for a replacement bulb, Phillips Crystalvisions are nice and give a nice crisp white light that doesn't seem to be too dazzling for other drivers, unlike HIDs. Although I beleice they dont have ECE or ADR51 compliance stamped on them, making them a defect but I've never had trouble from cops with it.

Posted: Thu Jul 09, 2009 9:56 am
by Graham
Yeah I did acctually try removing the blue parkers the other day and replacing them with the stock ones (one of my white t10 LED's is broken) after driving for about an hour, I forgot the engine would make everything hot :(

I love the look of the blue parking lights but i know a lot of people hate them and I can't see it when I drive anyway so I'll take them out tonight & replace with stock ones then buy another SMD off eBay :D

Posted: Thu Jul 09, 2009 10:05 am
by dumb&
Most of the SMD's on ebay are really really shit.

You go over a few bumps and the solder on them breaks and the light goes out.