Help! My dipped beam stopped working!

[aigoro]

this is an urgent one. drove home from work night before last and did not notice anything.

most of the roads on my way home from work are unlit so I would notice if my headlights weren't working, which is what happened last night on my way home. got to an unlit area and suddenly couldn't see. pulled into a petrol station to check. sidelights are working but dipped beam is not. main/high beam is working so i used that to get home but obviously had to turn this off everytime i saw an uncoming car or got close to a driver in front of me.

i find it unlikely that both bulbs or fuses would go at the same time, so it must be something else. what should i be looking for? any suggestions would be highly appreciated - i drove to work in daylight but need to get back home tonight!

 

[Nath.]

From fitting my HID kit I had a little problem and I found that a fuse went that protected only my drivers side dipped beam. So it would seem that they are fused indipendantly but don't rule out a second fuse for both sides .

Don't forget that there will be a relay as I doubt that the headlight switch will handle the current for 2X 55w.

Also IIRC there are threads on here about faulty headlight switches.

 

[RUM4MO]

Just a couple of points - but no answers sorry, there will certainly be a relay to handle the current the lights use, next, these light switches are prone to random failure and very easy to change while not too expensive - and they should be stocked by any VAG garage - but remove your one and take it in to the nearest VAG dealer so that they can compare P/N - BTW, do you have front fogs, if not and you eventually plan to retro fit them, then now is the ideal time to replace this switch with one that can control front as well as rear fog lights (sorry but I'm sure this is not your top priority at this time - but just an idea!).

 

[aigoro]

hi and thanks you both for your responses. does that mean the switch can fail partially? i thought if the switch was damaged, it wouldn't work at all. anyway, i'll check one of the fuses first, then if that doesn't work, the corresponding bulb (with the new fuse still in) and take it from there. in answer to your question RUM4MO, i don't have front fog lights and to be honest, i have never thought about retro fitting them. maybe later. for now, i just need to have proper headlights. it had to happen in winter didn't it?!

 

[Leigh15]

I wouldn't rule out both bulbs having blown either - it wouldn't be the first time I've seen it, although it's very unlikely

 

[aigoro]

it's not the fuses. don't have the right bulb unfortunately, i'll have to check when i get home. mine are the the old single reflector headlamps which use H4 bulbs, but my spare bulb kit has an H7 ...............which leads me to the next question:

since they are single headlamps and my main beam IS working, it can't be the bulbs can it?

 

[Leigh15]

Could have blown the dipped beam filaments if you had some kind of weird short or something - as I said, not likely but I have seen it

 

[aigoro]

i'll have to get my hands on bulb and check, then take it from there

 

[RUM4MO]

Strange things can happen to these bulbs as they are just a basic double filament lamp soldered onto an H4 fitting and they can end up with dry joints - seen that once. One other thing, last week I thought that my wife's Polo lights were dirty - that was until I took a look and discovered that the O/S lamp was u/s. Are you sure that your lights have not just failed one at a time, ie you might have been driving around with only one light working - and then the second one failed. This might be the time to buy some proper lamps from Halfords (seeing as you can not wait for internet ordered ones to turn up). Your comment about the fact that as you have one bulb with twin filaments showing that the bulbs are okay is not valid as the most used filaments may have blown, as I suggested one at a time. My previous advice about replacing the light switch was given as that part is easy to replace without tools, the real suspect, if the bulbs are okay, will still be the column light stalk - but to replace that means removing the steering wheel - and that would not be possible without tools etc.

 

[RUM4MO]

Any resolution to your problem yet? Remember to post answers and not just questions - so that others can benifit from your findings.

 

[billmc23]

aigoro, I sympathise with you - exactly the same thing has happened to my car recently. Dipped beam malfunction - but full beams and fog lights working perfectly.

I am in the dubious position of being without a manual, so I don't know which fuse applies to the 'dipped' circuit, nor indeed if there is a seperate circuit. I did however check the fuses one by one, and all seem ok. I guess the next step is to get a spare bulb (probabaly worth having one in the car anyway) and seeing if it works.

Please do let us know if you have diagnosed something in the meantime.

 

[nealo]

one of my bulbs went out about a month ago, but when i dropped the bonnet back down it came back on! was just a loose connection, so i took the bulb out and put it back in again, and it is still going strong.

 

[Nath.]

^^^^^that is normally a faulty bulb filament, it will fail again and if you thump it, it will shake the filament and make it connect and work for a while.

 

[RUM4MO]

^^^^^that is normally a faulty bulb filament, it will fail again and if you thump it, it will shake the filament and make it connect and work for a while.

Yes I agree it will just be arc welding the filament back together and will fail again soon - or you have a bad connection somewhere else.

 

[aigoro]

Could have blown the dipped beam filaments if you had some kind of weird short or something - as I said, not likely but I have seen it

you were right Leigh15, dipped beam filaments had blown. i don't know whether or not they blew at the same time. i could've been driving with just the one dipped beam without knowing. anyway, bulbs changed and working okay. thanks everyone.