My 2012 ML headlights and dipped lights seem to be much dimer than before... Any ide why this should be happening?

[tombell]

My 2012 ML headlights and dipped lights seem to be much dimer than before... Any ide why this should be happening?

 

[alecmascot]

Poor alternator output; cataracts

 

[wrdcc01]

Old lamps, yellowed plastic lens, moisture tarnishing lamp reflectors, weak alternator and or battery, voltage drop across supply or earth cables. Do they change brightness with or without engine running or being revved?

 

[Ted]

Check battery voltage.
Then check voltage across supply and return at bulb and let us know.
Are they incandescent or high voltage discharge (xenon) bulbs?

 

[tombell]

Hello ,
Thanks for responding so quickly
plastic lens are clear and clean, lamp reflectors not tarnished
they do not change brightness with or without engine running or being revved?

 

[wrdcc01]

Hmmm if there's no change in brightness that pretty well rules out the battery and alternator, and no discolouration takes out the lamp housing so you're left with old lamps, voltage drop on supply or as Ted questions, something faulty in the HID lighting units if you have these and not ordinary halogen. Time to get out the multimeter or at least visually trace the earth feed back to source and check for corrosion or loose bolts. You could do a quick check with a piece of wire from battery earth direct to the lamp fitting while it's on and see if that makes it brighter same with the power.
Just had another thought, have the lights got adjusted downward by accident? is there a leveling system either automatic or by rotary switch?

 

[tombell]

Thanks wrdcc01
I'm guessing they are Xenox... I'l maybe get Halfords to fit some LEDs

 

[tombell]

 

[tombell]

There is a levelling system rotor... I'll check that out

 

[Trickythemerc]

Fitting LED's is not the answer. They are not road legal and will fail the MOT on the light pattern, at night you will get light scatter and just annoy other road users.

 

[tombell]

I didn't know they weren't road legal. According to their site Halfords are selling them and customers seem to be very happy with them.

 

[SpikyMikey]

I didn't know they weren't road legal. According to their site Halfords are selling them and customers seem to be very happy with them.

They can sell them legally, as long as they state "For Off Road Use only" (which they do)

 

[tombell]

Thanks Mikey... I'm guessing someone supplies "legal" LEDs as they are fitted to some new cars

 

[W1ghty]

Thanks Mikey... I'm guessing someone supplies "legal" LEDs as they are fitted to some new cars

They might , but I don’t think self levelling Xenon MB lights can be swapped to LED without electrical issues ??

 

[whitenemesis]

No aftermarket conversion kit is legal for road use. If your model offers an option for different lamps you can convert using OEM parts for that version but it get very expensive.

From the MoT tester's manual..
"Existing halogen headlamp units on vehicles first used on or after 1 April 1986 must not be converted to be used with high intensity discharge (HID) or light emitting diode (LED) bulbs. If such a conversion has been done, you must fail the headlamp for light source and lamp not compatible.

This does not refer to complete replacement headlamp units which may be constructed with HID or LED light sources.

If a complete headlamp unit has been replaced with a unit that was manufactured with HID or LED light sources, it must not be failed for ‘Light source and lamp not compatible’ but it must meet all other requirements detailed in section 4 of this manual specific to the type fitted at the time of test."

MOT inspection manual: cars and passenger vehicles - 4. Lamps, reflectors and electrical equipment - Guidance - GOV.UK

Headlamp, position lamps, daytime running lamps, stop lamps, indicators, hazard warning lamps, fog lamps, reversing lamps, lighting ‘tell-tales’, trailer electrical socket, electrical wiring and battery rules and inspection for car and passenger vehicle MOT tests.

www.gov.uk

 

[tombell]

Pretty comprehensive response. Thanks Nemesis... I guess I'll stick with H& Halogens or Xenons or whatever My ML 250Currently has fitted.
Thanks again Tom

 

[SpikyMikey]

Pretty comprehensive response. Thanks Nemesis... I guess I'll stick with H& Halogens or Xenons or whatever My ML 250Currently has fitted.
Thanks again Tom

The easiest way to check what you have is to switch on your headlights and see if they do a startup routine 'dance', with the beam pattern moving up and down and left and right before settling into the ahead position.
If they do, you've got Xenons; if not you have Halogens.

 

[whitenemesis]

Perhaps try one of the very many upgraded lamps available? These give a greater light output at the expense of longevity
For example

Discover the new NIGHT BREAKER headlight bulbs | OSRAM Automotive

With the new NIGHT BREAKER headlight bulbs for xenon and halogen you get the most powerful car lights from OSRAM. Discover the new family now!

www.osram.com

 

[whitenemesis]

The easiest way to check what you have is to switch on your headlights and see if they do a startup routine 'dance', with the beam pattern moving up and down and left and right before settling into the ahead position.
If they do, you've got Xenons; if not you have Halogens.

Keeping in mind if they are bi-xenons the main beam lamps will still be halogens

 

[tombell]

Thanks Mikey and Nemesis... what am I gonna do when you guys pass away... mind you , I'm 77 so I'll probably beat you too it ;-)