Xenon headlight not working - faulty wiring?

[miko01]

Hi everyone!

Just had my Superb Elegance 2.5Tdi given it's end of 3 year first MOT today - failed on the passenger side headlamp.

Evidently they (Skoda dealer) reckon it is a loose connection rather than the actual bulb (which is not broken).So the light comes on sporadically and hence the MOT failure.

I have booked it back into them for Thursday to pull out behind the dash etc to try to discover fault.

Has anyone any idea what it could be - they were quite pessinistic regarding discovering the fault.

Otherwise the car is AOK!

And what a lovely car!

Regards

Mike

[Baker21]

If the bulb is coming on and off then it could be a number of things:

1) The counter conenctor has got some dirt or water in it causing an intermittant connection but I doubt this;

2) One of your fuses has come loose in your fuse box but again I doubt this;

3) The ballast has an intermittant fault but again I doubt this;

or the most probable cause is that your bulb is actually on it's way out.

[cheezemonkhai]

I had something on my octy where the non xennon light failed on the passenger side. They found it to be a wire had come off the back of the light switch. This also affected the rear light on that side though.

[miko01]

Thursday afternoon;

Dealers have looked at the problem using diagnostics and have found that if you turn on the headlights with the switch,turn them off and then turn them on again,the lights work okay.(This is similar to another posting).
However the MOT tester is not passing the car on the MOT because of this fact.
They will now try to discover more and will evidently involve the techies at M Keynes Skoda HO to help over the phone.
Carless now for today and tomorrow - have read all the relevant threads and suggestions re; igniter missfiring seems interesting - has anyone got any idea as I am now in a situation where my beloved Superb is not being allowed to be driven until this headlamp issue is sorted and the MOT subsequently passed!

Regards to all

Mike

[RADIOTWO]

Thats why you should get it MOT'd a fornight before it runs out, so you can get things sorted

Steve

[superb7]

i had a problem on my old renault with xenon lights the light would come on and flicker off the problem was the starter pack on the back of the light which ignites the gas in the bulb got it replaced and had no more problems apperently xenon bulbs should last the car out.

[johnjohnhealy]

While it could well be a faulty component, it is also common for HID lamps to behave in this way when they have reached the end of there serviceable life, the constant cycling on and off due to the bulb not being able to sustain a constant arc once it warms up, you often see street lighting doing this - coming on then cutting out after a few minutes (obviously not the sodium street lamps though before anyone jumps on me).

And HID/Xenon definately dont last the life of the vehicle, I replace on average 1 lamp every 6 months, but seeing as a normal halogen bulb will only last me a month at best most will never have to change the bulb (I do nearly all my driving at night).

[miko01]

Thanks for your answers - have learnt re; MOT timing too!

Shall pass these to the dealer.

Shall update as we get more news tomorrow and hopefully the car back!

Regards

Mike

[Baker21]

Originally Posted by johnjohnhealy

While it could well be a faulty component, it is also common for HID lamps to behave in this way when they have reached the end of there serviceable life, the constant cycling on and off due to the bulb not being able to sustain a constant arc once it warms up, you often see street lighting doing this - coming on then cutting out after a few minutes (obviously not the sodium street lamps though before anyone jumps on me).

Spot on, as I suggested above.

[Baker21]

Originally Posted by johnjohnhealy

And HID/Xenon definately dont last the life of the vehicle, I replace on average 1 lamp every 6 months, but seeing as a normal halogen bulb will only last me a month at best most will never have to change the bulb (I do nearly all my driving at night).

While Xenon may not last the life o the car it will however easily out perform a Halogen bulb up to 5 times over in most cases.

[johnjohnhealy]

Originally Posted by Baker21

While Xenon may not last the life o the car it will however easily out perform a Halogen bulb up to 5 times over in most cases.

Which is about right then if I have to change a Xenon every 6 months but a Halogen every 1 month. only downside is that 1 Xenon costs far far more than 5 Halogens!!

[Baker21]

Originally Posted by johnjohnhealy

Which is about right then if I have to change a Xenon every 6 months but a Halogen every 1 month. only downside is that 1 Xenon costs far far more than 5 Halogens!!

If I was replacing a Xenon Bulb every 6 months, I wouldn't be happy, way to expensive for that!!

[cheezemonkhai]

I have managed to keep halogens going for 2 years with almost exclusive night drives and about 24k miles.

What are you doing to them that make them blow monthly?
Stupid question but you don't touch the glass do you?

[johnjohnhealy]

No I dont touch the glass! the Superb uses H7 bulbs (on the non xenons) which dont last anywhere near as long as the octys (I think they are H4's? but they have 3 prongs instead of just 2).

I do beetween 10 & 12 hours of driving every night with frequent switching on and off so they do last as long as they are meant too, it's just the hours soon rack up, and with mainly town driving the bumps and potholes kill halogens.

As I said the Xenons last much much longer than halogens but they dont last forever, and financially they aren't worth it if you do night driving like I do, however, personally I find the light output makes them worth it.

[miko01]

Update at 2pm Friday - Skoda techies at M Keynes still unable to understand issues and are supposed to be talking to the factory to get an answer.
I had to take the train to work today as I obviously do not have the car!
Went to the station at 4.50am for the 5.01am to london,only to find it was not running today and the bus to take you further up the line left at 4.38am!
Went home and waited another hour for a train.
All because the MOT is failed because of a light that works if you turn the light switch on and off and on again,when it is perfectly working!
This is now getting to a legendary status - do we trash a £12.5K Superb because the light issue cannot be solved by the manufacturers themselves and the MOT is failed.
Bordering on the insane in my view.
Any help from anyone please!
Regards
Man not in hurry to get anywhere in his Skoda.
PS;don't forget - the light DOES work if the switch is turned several times!

[andy ellis]

Tell them to change bulb anyway and see if it cures problem. If it does....

[ScoobyChris]

Originally Posted by miko01

Any help from anyone please!

Without wanting to state the obvious, but have they tried a replacement xenon bulb in the unit?

Chris

[johnjohnhealy]

Sounds like it could be the ignitor but my money would still be on the bulb at this stage, the ignitor/ballast unit should repeatedly send the bulb 50,000 volts untill it lights then stabilise down to 20,000 volts or so, some ballast/ignitor units will constantly try and start the bulb, some will try a maximum number of times then give up, which is possibly whats happening with yours, and if the bulb is aged it can take longer for it to ignite so possibly the repeated turning off and on is enough to eventually get the bulb started.

If the same happens with a new bulb then the ballast/ignitor unit must be replaced, unless it's something really simple like a relay or faulty switch.

[spencem]

I had a similar issue with my old Ren-NO, it turned out to be one of the self-leveling sensors, it was so far out of whack that the unit shut down so as not to blind airline pilots.

Good luck

[WW_VRS]

Slightly OT but why do you keep turning the lights on/off frequently (rather than just keeping them on for the duration)? (note this was not in regard the original post)