My LED's keep burning out., Why? Options

[richee3]

I have been using LED's in my gauge cluster for a little over 2 years now. The first set of LED's I had were cheap-o blue LED's from Ebay. After a while, the LED behind my fuel and engine temp gauge went out. But it didn't go all the way out. It started flashing on and off, between all the way off, all the way on, and about halfway in between. After a while, it settled down to being about halfway on, but it would still flash. I chalked that up to cheap LED's, and moved on to white LED's from v-leds.com. I got them put in last Christmas. Last Spring, same thing happens, in the same spot. The bulb behind the fuel/temp gauge starts flashing like it's burning out, but never goes all the way out. I moved it around, and no matter where I put it, it still flashed. So I replaced the bulb with a spare that I had, and a few weeks ago, it started doing the same thing. Now, the other LED's behind my speedo and tach, in my turn signal indicators, and in my key ring are all fine. Nothing ever happens to them. It's always the one behind the fuel/temp gauge, and it's always the bulb going out. I can move it anywhere and it still flashes. I find it hard to believe that it's just coincidence that 3 different LED's have gone bad, when they were all in the same spot. So... What's up with my LED's? Or, I guess, what's up with my gauge cluster that is making them burn out like that? I have a video of what they are doing, if anybody needs to see it.

Thanks in advance for any insight you guys have.

[SinisterSinner]

I finished putting LEDs in my cluster (along with replacing all of the SMD LEDs on the stock headunit... we'll save that for later).

The dimmer circuit definitely seems like a "dumb" circuit, where it's a pot that controls the +12 to the lights. I dimmed my LED clusters back and forth to no problem. Again, I've never come across an LED that will burn out from under-voltage. I'm not saying it isn't possible, but I've just never experienced it, no matter how cheap/expensive the LED (and I've been working with LEDs in hundreds of different electronic devices for well over 6-7 years). I feel as if you may have just gotten unlucky.

BTW, my cluster looks GREAT with these LEDs. They're 4000mcd 5mm LEDs I picked up from Mouser. Bought 50 of them for $16 (32 cents a piece... very expensive for bulk, cheap LEDs IMO). Link: http://mouser.com/Search/ProductDetail.asp...y593-VAOL-5LWY4

Pics will come soon as I'm done with my CC.

WHAT!?!?!?!?!16$ for 50 4000mcd LEDs!?!?!?!!?!?! thats madness!!!, I get american's Best quality LEDs 50 of 13000-23000 MCDs for about the same price!, I'm going to redo my cluster again and remake Lexus RX's 450h LED dimming panel blue lights, and when I take my old LEDs out, Ill make a DYI on how to make those custom bulbs , that way you wont have that LEDs burning out problems, and without having to make anything too complex like custom circuit boards or having to add capps , well I dont need capps because my battery is new, the old one almost screwed up my starter, but luckily I have a Celica, not a honda or an chevrolet lol, thats why my starter still good

Don't mind the ridiculous resistor cluster. It's a set of several resistors in parallel to give me 480ohms to lower the 12v source to light the single LED. I didn't have anything near 480ohms for resistors, so I just went with what I had

I dont recomend having the resistors being toguether like that, they can over heat!, try to separate them a little, so that they could work a little cooler and last longer

QUOTE (richee3 @ Dec 5, 2009 - 12:41 AM)
^^ I just had my alternator rebuilt a year ago next month, and the guy who rebuilt it was shocked when he tested it. He claimed it put out more power than most other alternators he has tested. I think he lied...



It depends on how many amps it is. Normally your car should put out 14v with the headlights on, but if the amps are too small that voltage is going to dip down when you press your brakes, or your fans kick on or you roll up your windows. Then you will see a dip in the voltage that could cause issues with the leds.

dude, I roll my windows up, close the sun roof, while stepping on the brake and the car with the fans on and the ac on low and I do that just about everytime I get out of my car around 3-4 times a day At least! and I have LEDs allover my car and not even a single one has gone bad, exept for the gas one which is on all the time ever since I did the LED combersion bulbs, besides that I used to have a bad battery just like 2-3 months ago, and now I have a new one and everything works 100% and no LEDs burnt, so it cant be the voltage unless is too high instead of low, because when you step on the gas the voltage goes up about 1/2 of a volt, maybe the guy who rebuilt the alternator was right, its too strong for the LEDs, just to test you could try changing the resistor and put stronger ones with higher ohms, they LEDs will glow less, but they might not burn out on you as quick as the other ones. good luck
-Adan

This post has been edited by SinisterSinner: Dec 6, 2009 - 12:23 AM

[solidxsnake]

Don't mind the ridiculous resistor cluster. It's a set of several resistors in parallel to give me 480ohms to lower the 12v source to light the single LED. I didn't have anything near 480ohms for resistors, so I just went with what I had

I dont recomend having the resistors being toguether like that, they can over heat!, try to separate them a little, so that they could work a little cooler and last longer

There is no way a single 20mA LED is going to pull enough current to heat up 5 1/4W resistors

Ironically enough, I noticed today the red/blue LEDs I had lighting the thermostat temp knob aren't lighting. I gotta pull apart my CC unit and check if they burned out. It's quite possible one or both of the red ones burned out, they were rated to 2.3-2.5v I believe, which means putting them in series with two blue LEDs would lead to a slight overvoltage.