MOT question on lights

[E21_Ross]

Hi guys,

Have a small problem with 2 of the 4 lights on my car (4 separate lights in the grill). appears there is a dodgy earth connection to the middle 2 lights which are the full beams, and these do not work. however, the outer 2 lights still work for dim, and normal night driving. if i put the indicator stalk to full beams, the outer 2 lights go brighter and are as bright as the full beams were when all 4 were working (so the outer 2 lights are taking over the role of the other 2).

so, the car has effectively the same lighting power as before, and is just as safe of course, but would this constitute an MOT fail because 2 lights aren't working? what if i put a cross of black tape over the 2 lights for the MOT? as said, lighting power it's still fine as it normally would.

just don't fancy having to trace an earth cable all through it's course to find the fault if i don't really need to.

thanks guys, much appreciated.

Ross.

[martin mrt]

Remove the two inner lights, if it's not there it's not testable and as the outer lights are providing side,dipped and main beam you will have no issues

[paintman]

This may help. States the requirement of obligatory lamps.
http://www.motuk.co.uk/manual_120.htm

You can't just put a bit of black tape over the odd lamp you don't feel like sorting out. Its all the lights not fitted or all the lamps properly masked.
http://www.motuk.co.uk/manual_110.htm

Edited by paintman on Sunday 10th October 11:16

[Eggman]

Presumably it's a 316 then, with twin filament bulbs in the outer pair? If so, the centre pair are driving lights and there's no requirement for them to be working.

(iirc there was an accessory grille with them in that was popular at the time. There's probably a relay somewhere that is dud).

[E21_Ross]

hmmm

Note: Main-beam and dipped-beam functions may be provided by a
single pair of headlamps.

further reading suggests i need to get it sorted.

never mind, thanks chaps.

[E21_Ross]

Eggman said:

Presumably it's a 316 then, with twin filament bulbs in the outer pair? If so, the centre pair are driving lights and there's no requirement for them to be working.

(iirc there was an accessory grille with them in that was popular at the time. There's probably a relay somewhere that is dud).

yes, has twin filament bulbs for the outer pair, and it has the accessory 4 lamp grille. so, do the 2 inner lights not need to work?

as said, the outer 2 lights (the main driving lights anyway) now provide full beams too, which are just as bright as normal full beams when on full beams.

Edited by E21_Ross on Sunday 10th October 11:22

[jagracer]

Do the outer lamps provide main and dipped beam so if all the lights worked properly you would have 4 main beam and 2 dipped, I.E the outer two?

[E21_Ross]

jagracer said:

Do the outer lamps provide main and dipped beam so if all the lights worked properly you would have 4 main beam and 2 dipped, I.E the outer two?

when the inner 2 worked, the outer 2 did not get brighter on full beams, they stayed as normal night driving and the inner 2 went to full beams. when driving normally at night (i.e. no full beams) the outer lights were on and the inner lights were off.

if driving around at night with no need for full beams, the outer lights are the same brightness as they have ever been. it's just the outer lights now work as full beams also.

[Eggman]

Check with your MOT man - I think they should be fine as they are; they're not 'obligatory position lamps' so they're excluded from the test. (Unless it's a 320 or 323, in which case they're not!)

[Eggman]

E21_Ross said:

if driving around at night with no need for full beams, the outer lights are the same brightness as they have ever been. it's just the outer lights now work as full beams also.

Sounds like there might have been a relay energised by the main beam circuit that switched the current from the 'proper' main beams to the accessory lights and said relay has now expired*. If so, that was an interesting way of wiring them up... I suspect that the driving lights were just jolly bright so it looked like the main beams were still dipped.

Either way, as long as you've got a main beam and a dipped beam the driving lights don't need to work. (Think of all the XR3s that used to drive around with broken and rusty looking driving lights pointing at the sky - at least some of them must have had MOTs!)

(ETA: * It occurs to me that if there was ever such a relay there'll probably be a switch somewhere otherwise there'd be no point doing it this way. Had the car long? Been playing with any mystery after market looking switches lately? )

Edited by Eggman on Sunday 10th October 11:45

[E21_Ross]

Eggman said:

Check with your MOT man - I think they should be fine as they are; they're not 'obligatory position lamps' so they're excluded from the test. (Unless it's a 320 or 323, in which case they're not!)

that is a very valid point. i might phone them up monday and ask about it, clearly explaining to them that the 2 centre lights aren't obligatory, and the car didn't come with them out of the factory.

[E21_Ross]

just spoke to my MOT tester, he said it would pass