Number plate bulbs - housing melted

[heeman10]

I don't think I'm alone here. My LED number plate bulbs started throwing up errors a handful of times a month...then once a week...then more frequently until they gave in completely. I bought a set of "CANBUS bulbs", which work directly off the car's battery, but not when fitted to the housings.

I investigated further today by removing the tailgate trim, followed by the tailgate handle/number plate bulb assembly. It's in two parts - there is a bridge piece which slots into the back of the handle. When you remove it, it is nothing but a lightweight plastic moulding which houses the tailgate handle switch, and the two pairs of terminals that form the "roof" of the number plate bulb holders, as viewed from the number plate recess when fitted to the car. Sure enough, both terminal housings have melted and cracked, so I'm not surprised none of my bulbs worked.

As expected, Audi don't sell the very simple bridge piece individually, you have to buy the whole assembly, including the main body and tailgate handle etc, at a cost of £58! I then rang our friend Dave at Stoke Audi, who is sorting it out for me at £53. Better, but still one hell of a price to pay just for the sake of LED bulbs generating too much heat. I'll be more than a little dubious about trying my CANBUS bulbs in the new housing I just don't want the crappy standard yellow bulbs!

Sorry to go over the ASN sore point of LED bulbs in a new thread, but hopefully by documenting it in this way, others suffering endless bulb failures will know their probably culprit.

Pics:

The assembly with the bridge piece removed from its slots:

One of the melted and cracked bulb housings:

Part number for the tailgate handle/switch and bulb housing assembly:

****** LED bulbs!

 

[heeman10]

And just because I might as well ask, in this, the 628th LED number plate bulb thread: Has anyone found any halogen bulbs that give off a white light? My LED sidelight bulbs were no good, but I was able to find some good halogen equivalents. I've just trawled around the net without much joy, since people are only selling LED bulbs now.

 

[FranA3]

ive not had a single problem with my leds that i bought off ebay they only cost £8 delivered they have been in there for months not one light out warning and no melting at all get some of them matey

 

[heeman10]

You are just the kind of person I don't want to hear from right now! Please go elsewhere!

 

[FranA3]

 

[heeman10]

My LED bulbs were okay for six months or so I think, but then started playing up more and more until they gave up completely. It might not be a bad idea to check inside your light housings, just to be sure matey!

 

[mike foster]

Is there no way you guys could cut a ventilation hole in the top of the lampholder to allow the heat to dissipate ?

The heat is not actually off the led's, it's off the resistors built in for canbus error purposes.

 

[heeman10]

mike - Correct, an LED bulb gives off nigh on no heat whatsoever, but of course without the resistors, our bulbs no worky. I have a brand new pair of "CANBUS safe" bulbs, with the great big finned heat sinks on them, but they're so close on shorting out across the bulb holder contact arms that I'm a bit unsure about their safety as well.

As for cutting vent holes - I'd rather not, since the A3 is prone to rear washer hose leaks inside the tailgate. I haven't had that problem with mine, but would rather not have it shorting out if it does leak down there.

 

[scottie123]

Also remember that normal festoons give off a fair bit of heat also

Perhaps it is down to the style of led fitted. The ones I have, have a heatsink, but it doesn't pertrude much more than the o/d of a standard festoon bulb. Yours as you say, Have the great big finned heatsinks, hence it will be closer to the plastic on the trim handle, and so melt it.

I would check mine to see if there is any sign of melting, but the are so sh1t to get back in , I Dont want to mess with them

Just a thought anyway

 

[FranA3]

My LED bulbs were okay for six months or so I think, but then started playing up more and more until they gave up completely. It might not be a bad idea to check inside your light housings, just to be sure matey!

yeah i'll pull mine out at some point its just they are crap conections so dont want to mess round with them too much while they are working lol , on mine ive got the halogens set to drl so the headlights and taillights are on all the time while im driving still no probs so far with them

 

[heeman10]

scottie - My CANBUS heatsink bulbs have never illuminated whilst fitted, it was the LED bulbs fitted prior to the CANBUS bulbs that did the melting, and they don't have heat sinks on them. So...the lack of heat sink COULD have been the cause. Do YOU fancy guaranteeing that my heat sink bulbs WON'T melt my holders? I sure as hell can't, but think the logic would suggest that they would be safe, if everyone else is getting by with theirs. Do you have a pic/link to your bulbs scottie? These are mine:

Pretty huge heat sinks!

Fran - I always drive with my lights on too, so they will undoubtedly have done hundreds of hours of service, but the result was molten innards. I wish there was a decent scrappy near me!

 

[FranA3]

wow they are big heatsinks on them mate hopefully they do the trick i think they would certainly get rid of excessive heat with that size sinks on them , i used to even before i had them set on vag-com to be drl's so like you they have done alot of hours of running

 

[mike foster]

I'm sure you are aware that heatsinks get very hot as well !

The clue is in the name !!lol

Finned heatsinks like that usually rely on a constant airflow over them to provide cooling. If they are not in an airflow then they just get hot !!

Sorry chaps - just my two penneth .

 

[heeman10]

Mike - A bit like KP nuts containing nuts, according to their ever-so-helpful packaging!

Fran - They are massive! The weight of them makes them want to swing down, which is fairly foolish. I think I would be far happier with some decent white filament bulbs.

 

[Sam Dawson]

@ heeman10 I purchased the same canbus bulbs as yourself.
Had nothing but trouble with them, I managed to get one working and I put the original bulb back I'n the one that didn't work, the original doesn't work now, and also the one that did work doesn't now and neither does the original!

 

[heeman10]

Daws88 - Maybe it's time to look up inside the housings and see what shape they're in buddy I hope yours aren't ****** too..