Failed NCT: dipped beam out of focus?

leatherjacket

My Golf 5 failed the NCT this morning. The tester said the headlights needed to be focused.

Any idea what this means? Not sure if it means the vertical alignment is off, or is there an actual issue focusing the light from the bulb.

porsche boy

Nobody will be able to answer that on here. Go to a garage with your NCT failure sheet and let them resolve it

biko

You will probably need a professional garage for this.

Did someone change the bulbs recently? If they are seated improperly it could be the issue.

I failed on the same thing a while back in a mk5 golf and it was actually the build up of gunk on the glass that was causing it nothing to do with the adjustment of the lights. So if the glass is a bit foggy this could be the cause.

biko

I actually have NCT tonight and will give the glass a once over with toothpaste


EDIT
Before https://s22.postimg.cc/50fvlm68h/image.jpg
After https://s22.postimg.cc/y2u5ojne9/image.jpg

Irish Steve

There are several possible reasons for a fail on headlights, depending on the make of vehicle and the headlight type. The vertical alignment is the most common problem, and that can be affected by the bulb being incorrectly fitted, the car taking a minor ding on the front bumber, which can move the entire headlight unit, or the bulb itself has deteriorated mechanically, and the filament has moved inside the glass envelope. On a newer car with adjustable lights, the motor that moves the bulb assembly may have stuck, or the lens may have become detached from the motor, so the position is wrong, even though the motor control on the dash is set to the correct setting.

In some cases, the horizontal alignment may be out, some headlights can be adjusted to set this correctly, and similar reasons can apply.

The other possible issue is that the lens of the headlamp has deteriorated with a combination of heat and time, and is no longer letting the light pass, so the test machine is not seeing the correct pattern of light. Had this happen this week on a 05 Almera, the light pattern was very much reduced when compared to the other side, the only option in this case was a replacement headlight, as there's no way to fix the issue with the internal lens unit, and cleaning the external lens didn't change anything.

Ideally, it needs to be looked at by a garage that has a beam setter, so that they can see the alignment and clarity of the light pattern being produced by the unit.

damon5

biko wrote: »

I actually have NCT tonight and will give the glass a once over with toothpaste


EDIT
Before https://s22.postimg.cc/50fvlm68h/image.jpg
After https://s22.postimg.cc/y2u5ojne9/image.jpg

+1 on the toothpaste as never had a problem at the nct and thats with a spurious headlight too