Headlamp aim, UK MoTs

[UAB807F]

Hi folks,
I've tried & failed at the search option, so does anyone have a nice simple guide to headlamp aim for the Uk MoT test ? Something like "at 3' away the centres should be 2'3" up the wall dead ahead on main, and 2' up the wall and offset to the LHS by 6"-ish on dip" ? (well, that's roughly where they are now)

I've measured the light centres against the garage wall and sure enough they flick down when they're supposed to, but when I read the current regs it goes on about "kick up to the left", percentages and other such things which I'm sure I've never seen before.

I realise I could just ask the garage to do it but I'd not like to present the car with obvious faults.

TIA, Brian

[Robbie693]

Hi Brian,

Do you have a manual? There is, in the Plus 2 manual at least, a diagram for headlight alignment. I don't have the manual with me right now so can't give you the figures but I seem to remember that the lights should aim straight ahead, i.e. at the same height as the light centres, on full beam from about 10 feet away from the wall or aiming board. The kick up of the pattern should be handled by the lenses so is not adjustable I think. Perhaps someone will confirm/correct me on this.

Robbie

[terryp]

Also (I've just done them my Caterham for LHD) once you are happy go back and forth up to the wall and you will see whether they are out from side to side, adjust until they don't move.

I had mine checked at a local garage , well I did the checking the chap in the garage just moved his machine in and out. they were just a little high.

Terry

[UAB807F]

Hi Brian,

Do you have a manual? There is, in the Plus 2 manual at least, a diagram for headlight alignment. I don't have the manual with me right now so can't give you the figures but I seem to remember that the lights should aim straight ahead, i.e. at the same height as the light centres, on full beam from about 10 feet away from the wall or aiming board. The kick up of the pattern should be handled by the lenses so is not adjustable I think. Perhaps someone will confirm/correct me on this.

Robbie

do you know, I'd never even thought of looking in the manual ?

But yes, I've found the section on adjustment and it does state pretty much what you've said about being straight ahead, presumably on full beam, with the dimensions taken from the car headlight centres. Surprisingly that's almost what I'd been working on, using a spirit level plus laser dot to shine on the wall, marking with masking tape & then adjusting the beam until it was central. The snag is that the manual says around 25' distance to the marker board, and my garage isn't that long !

A good tip about rolling the car in order to see if the centres move. I'd not thought of that, or even read about it before but it sounds easy enough to check.

I'm sure our local garage will adjust them for me, but I didn't want to take it in being so far out that it becomes a "hey come and look at this ! " moment. Thanks guys.

[billwill]

My big Renault Espace has little motors in the headlights so that they can be aligned from a control on the dash.

I've pondered from time to time on replacing the Lotus adjusting studs with an electrically alterable adjuster.

[Galwaylotus]

when I read the current regs it goes on about "kick up to the left", percentages and other such things which I'm sure I've never seen before.

The modern headlamps have a defined pattern that has a definite upward slope to the left. This wasn't the case with the older sealed beam lamps which merely have a hot spot. The newer lamps are far more effective and are much easier to align.
For a good illustration of the light patterns for the different types go to http://www.ncts.ie/pdf/nctmanual.pdf and look at pages 49-51.

[bcmc33]

My big Renault Espace has little motors in the headlights so that they can be aligned from a control on the dash.

All modern cars have adjustable headlights - they are set to the highest point for the MOT.

On two occasions I've set my Elan headlights as per the manual only to be told that they are too low on MOT day. After the first time I've never bothered to replace the chrome trims - in order to effect a quick adjustment should it be required.

[UAB807F]

Funny you should mention about leaving off the chrome rings, I've decided to do the same for next week. I can't help but think the modern regs are a classic example of getting too wound up in technicalities when they're talking in terms of 1-2% acceptable bands or failing because they're set too low. Especially when you look at the (original) heath-robinson looking lift system on my elan !

Incidentally for anyone else reading this later on, the link by Galwaylotus above is a much better explanation than I'd found on the UK gov. sites - thanks again for that Bill.