An appeal to the collective knowledge here and perhaps alerting others to a potential problem.

 

I got a warning symbol and the notification “Left Daytime Running Light faulty”. Sure enough, it was only giving off an orange glow, so I assumed the bulb was on its way out.

 

Before changing it, I first checked all the light functions and found that the left sidelight was barely glimmering too – but main beam looked OK. I removed the bulb and was surprised to see that both filaments looked good. So I tried putting it back in and now all the lights worked correctly!

 

Suspecting a poor earth, I removed the bulb holder again with the intention of giving the contacts a smear of De-oxit as a precaution. I then noticed that the lowest of the three tabs on the holder was blackened and when I touched it found it was as hot as hell! On close examination I saw that the surrounding plastic had suffered some slight heat damage. Using a mirror I could also see that the corresponding tab in the plastic collar that the holder rotates into at the rear of the reflector had the same symptoms.

 

I came to the conclusion that the bulb-holder had somehow worked loose (or never been fully tightened), that the lowest tab was the shared earth (I should have confirmed that, but forgot) and that the power draw of main beam had caused the contacts to heat up; over time the burning had increased the resistance which became too much for the lower power draw of the sidelight/DRL filament to overcome.

 

Ideally I wanted to clean up both sets of contacts. As far as I can see the collar is held in place by a single screw which I removed but, try as I might, I could not get it to separate from the reflector and I was wary of using too much force in case I broke something. In the end I just cleaned up the tab on the holder, gave it a good dose of De-oxit and then rotated it back and forth in the collar to clean both sides. I then tightened it up as firmly as I dared; the lights all worked correctly and after a few minutes with main beam lit, I removed the holder and to my relief found the tab to be perfectly cool. I repeated this test three times so it seems that it is now making good contact and is not heating up.

 

So....two questions:

 

      Is my conclusion and cure OK? - or am I missing something? (I know getting the dealer to look at it under warranty would be best, but they're thirty miles

      away and I don't want to waste a day of my life while they faff about with something that is hopefully no big deal)

 

     Has anyone managed to remove the mounting collar from the rear of reflector? I would still like to inspect/clean its contacts properly.

 

 

I'm not sure what lights you've got but at the first service I had the power modules replaced for the lights on my vRS.

The dealer told me it was because there was a risk of overheating & fire.

Sounds like a non-vRS model, or at least one with the bi-xenon's and LED DRL strip.

 

Stopping the excessive heat is a priority which you have done, it doesn't take much for an under bonnet / electrical fire to start.

 

When is the car due it's next service? Now you have cured the issue I'm sure it can wait until the next dealer visit but I'd wanting the damage parts re[laced under warranty.

 

Edited 23 May, 201610 yr by silver1011

Sorry, should have made it clear, it's halogen.

 

Silver 1011, - good thinking - but unfortunately it's only just had a service so it'll be a while before it's due back at the dealers.

If its under warrenty & the lights are not working correctly, why not just take it back to the dealers for a repair?

If you try to fix it yourself & something else goes wrong in the future they can always use this against you the next time as you have made a non-standard repair.

Agree with above. Try getting the Skoda to do their job. Especially if it just had a service - it sounds like a reasonable claim.

If you see some molten plastic, they shall replace it too.

 

Your conclusions seem fine - if contacts were not clean, a small resistance build up acted as a heater. High-amp load like a halogen lamp can turn even a fraction of ohm into a heater.

In case you would have to do it all yourself, start with brushing off the contact contamination with a small metal brush (soft one) and then treat it with contact spray (don's use too much / overspray the reflector). Check the contact resistance afterwards - use DVM across the bulb and measure differential R or direct if you can access the contact. Molten plastics remain damaged though...

 

 

Your conclusions seem fine - if contacts were not clean, a small resistance build up acted as a heater. High-amp load like a halogen lamp can turn even a fraction of ohm into a heater.

In case you would have to do it all yourself, start with brushing off the contact contamination with a small metal brush (soft one) and then treat it with contact spray (don's use too much / overspray the reflector). Check the contact resistance afterwards - use DVM across the bulb and measure differential R or direct if you can access the contact. Molten plastics remain damaged though...

 

Thanks for the re-assurance.

 

I've just checked again today and the contacts remain cool to the touch, so I guess I caught it in time.  I think you and other posters are correct - I'll have to bite the bullet and waste time going to the dealers, Can't see them arguing much over something as obvious as melted plastic.