How do I know when the main beam is pointing in the right direction?

(NB "the main beams adjust with the dipped beams" is the wrong answer - on my car, an '06 TDi Ambiente estate, the main and dipped beams are adjusted entirely independently.)

Dipped beams are easy - there is a distinct angled line in the beam pattern which you can use to set the height and horizontal position of the beam.

Main beam is more difficult, because there is no pattern in the beam - it is simply an even flood of light with no obvious way of identifying the centreline.

Anyone know the accepted method?

The way i set my main beam up is to find a dark industrial estate etc and shine the lights on a wall in the distance, with the dipped beam bulb covered (bit of card taped over the lens) you can then clearly see just the main beam (i also find it useful to cover the bulb you are not adjusting) this can be a bit of trial and error but has always worked for me for setting up the main beam (as well as spot lights).

It's that basic, eh? Thanks, Gizmo.

Make sure you are on level ground when you set it up though otherwise you will only be looking at trees when you get on the road !

Where is the adjustment for the main beams ??

Take it to a friendly MOT centre and get them to stick it on the beam setter. Only way to be sure..............

Where is the adjustment for the main beams ??

On my car the adjustment for the DIPPED beams is accessible just by lifting the bonnet - one large plastic Allen socket for vertical and one for horizontal adjustment, just inboard of the light unit.

The adjustment for the MAIN beams is, IIRC, round the back (I haven't got the car with me at the moment but I seem to remember you have to access the inside of the main beam unit from the back - I think there's a rubber cover which you have to remove).

I'll check later when the car returns and confirm this.

Take it to a friendly MOT centre and get them to stick it on the beam setter. Only way to be sure..............

Are you sure they check the main beam? I thought they only worried about the dips...

On my car the adjustment for the DIPPED beams is accessible just by lifting the bonnet - one large plastic Allen socket for vertical and one for horizontal adjustment, just inboard of the light unit.

The adjustment for the MAIN beams is, IIRC, round the back (I haven't got the car with me at the moment but I seem to remember you have to access the inside of the main beam unit from the back - I think there's a rubber cover which you have to remove).

I'll check later when the car returns and confirm this.

Cheers.

Cheers.

OK, I was almost right. The MAIN beam adjuster is on the back of the unit, not inside it as I previously wrote. It's an Allen socket with a cross-head inside it, so you can turn it either with an Allen key or with a cross-head screwdriver.

Hope this helps.

OK, I was almost right. The MAIN beam adjuster is on the back of the unit, not inside it as I previously wrote. It's an Allen socket with a cross-head inside it, so you can turn it either with an Allen key or with a cross-head screwdriver.

Hope this helps.

Main beam is adjusted via 2 adjusters on the back of the headlight unit - towards the 'inside' of the car, ie towards the radiator. There is an Alan Key adjuster which adjusts the up/down of the main beam and diagonally across the rubber cap there is the adjuster for the left/right movement. main beam should be adjusted so that the centre of the beam is just over the the point where the angle part of the dip beam meets the flat part of the dip beam - this can be difficult to see by eye with both beams on but if done in the dark againsta flat surface it should be possible to get a reasonable adjustment done.

Dip beam is adjusted from the front of the car via the 2 adjusters to the side of the headlight unit - to one is up/down and bottom one is side to side.

Thanks lads, I've been meaning to adjust "air raid" main beams for some time now. Cheers.