Rear LEDs totally gone!

Trap 125 · Post by **Trap 125** » Sun Dec 30, 2007 4:05 am

A couple of nights ago i noticed that all but 4 of my LED rear lights were not working, meaning I currently have no rear lights or brake lights. The last couple of nights I have been running the car with the rear fog lights on and luckily the centre brake light is still working. Obviously this is illegal and need to get it fixed asap. I have tried the technical 'wiggling the cables' suggestion on another thread but to no avail. Anybody got any ideas/solutions on how to solve this problem? The car is now out of warranty.

Many thanks. Ossie.

Rich H · Post by **Rich H** » Sun Dec 30, 2007 9:24 am

I assume that as the LEDs blow (Which they shouldn't!) the current through the others goes up shortening their lives... Not good.

Check all the fuses first, but I think the brakes and the rear reds are on different circuits.

If its not fuses pull the unit out and see if 12V lights it, if it does then its wiring if it doesn't then its time for a new unit.

hiscot · Post by **hiscot** » Sun Dec 30, 2007 10:04 am

could you not wire a inline resistor into the power cable ,so next time that blows instead off the led
i have done this with my home made shift light but copyed the specs from another forum
you should ask an electronics expert if its feasable and what resistor would be required if any ?

Rich H · Post by **Rich H** » Sun Dec 30, 2007 10:31 am

hiscot wrote:could you not wire a inline resistor into the power cable ,so next time that blows instead off the led
i have done this with my home made shift light but copyed the specs from another forum
you should ask an electronics expert if its feasable and what resistor would be required if any ?

Calling Robin...

robin · Post by **robin** » Sun Dec 30, 2007 1:44 pm

I haven't seen the Lotus LED light system so don't know for sure, but I would expect there to be voltage regulator of some sort to limit the voltage supplied to the LEDs. Typically LED arrays are made by stacking LEDs in series to get close to the required voltage (e.g. Vf on an normal red LED is ~2v, so you would stack 6 or 7 of them, then put a low value resistor in series to drop the remaining volts, plus probably a zener diode in parallel to the stack to limit the voltage to some maximum in case of overvoltage).

I would check fuses and wiring first; I don't have a wiring diagram for the Toyota engine cars, so cannot say exactly what to check, but likely candidates are the inline connectors that are probably lurking in the boot and subject to corrosion from moisture trapped in the boot.

Cheers,
Robin

meatball · Post by **meatball** » Sun Dec 30, 2007 2:11 pm

CALLING ALI (SLS).......

ruadh08 · Post by **ruadh08** » Sun Dec 30, 2007 4:19 pm

robin wrote:I haven't seen the Lotus LED light system so don't know for sure, but I would expect there to be voltage regulator of some sort to limit the voltage supplied to the LEDs. Typically LED arrays are made by stacking LEDs in series to get close to the required voltage (e.g. Vf on an normal red LED is ~2v, so you would stack 6 or 7 of them, then put a low value resistor in series to drop the remaining volts, plus probably a zener diode in parallel to the stack to limit the voltage to some maximum in case of overvoltage).

Cheers,
Robin

In the old days we just used to put a new bulb in!!!

Rich H · Post by **Rich H** » Sun Dec 30, 2007 5:09 pm

Bulbs are alot cheaper than a whole light cluster too!!

robin · Post by **robin** » Sun Dec 30, 2007 7:06 pm

I will be able to repair any broken LED cluster (ignoring impact damage), so don't buy a new one ...

Cheers,
Robin

Trap 125 · Post by **Trap 125** » Mon Dec 31, 2007 1:18 pm

Many thanks for all your replies. Robin, I will check the fuses but if I have no luck and if its ok with you, can I get in touch in the new year with regards to trying to fix the lights?

Thanks again,
Ossie

robin · Post by **robin** » Tue Jan 01, 2008 2:36 am

Sure thing - if you're in Edinburgh area then we'll sort out popping round and taking a look ...

Cheers,
Robin

Caveat Lector · Post by **Caveat Lector** » Thu Jan 10, 2008 12:23 am

Has anyone experienced intermitent problems with the LEDs? My wife followed me home the other night and when we got home she told me that some of the LEDs were out. I looked and she was right, but when I went out tonight to check which ones were out they were all OK. Either the problem went away on it's own, or my wife and I are imagining things (not impossible, I'm feeling closer to senility every day)

ChrisG · Post by **ChrisG** » Thu Jan 10, 2008 2:06 pm

This is a common problem with 07 model exige & elises, MMC told me there was a bad batch and the supplier has now been changed as a result. My car is getting a replacement set.

If it is under warranty give MMC a call.

delands · Post by **delands** » Fri Feb 08, 2008 12:17 am

Is there a delay in getting LED light clusters? Less than 300 miles of night time driving and a couple of them are out on the offside one!

kirk · Post by **kirk** » Tue Feb 12, 2008 8:13 pm

hi guys, a few weeks ago the LED light units were on back order from lotus. a know that there has been a delivery of LED light units to MMC ( not sure how many tho ) so best to phone MMC asap to try and reserve some for your own cars. also Lotus has changed there supplier of the the LED light units so there no longer should be a problem with them.cheers.

Scottish Elises

Rear LEDs totally gone!

Rear LEDs totally gone!

Re: Rear LEDs totally gone!

Re: Rear LEDs totally gone!