LED Bulbs in Halogen Lights

Kenai · 12 Jan 2021 at 13:21

...are now explicitly mentioned in some amendments made to the MOT testing manual yesterday.

https://www.gov.uk/guidance/mot-ins...ssenger-and-light-commercial-vehicles/updates

4.1.4 Headlamps - Compliance with requirements - Changed sentence from 'Existing halogen headlamp units should not be converted to be used with HID bulbs. If such a conversion has been done, you must fail the headlamp.' to 'Existing halogen headlamp units should 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.'

I'm sure this update will please some and irritate others

Kenai · 12 Jan 2021 at 13:26

VaderDSL said:
Presumably if halogen headlamp unit with LED from factory, then it isn't classed as converted? The new Fords come with Halogen units, with LED bulbs from factory.

If it has LEDs in it from factory and not halogens, then it's not a halogen headlamp? :confused:

Kenai · 12 Jan 2021 at 13:32

VaderDSL said:
I'm probably getting confused between the terminology are halogen headlamp units referred to in this instance the reflector types? As in if it has halogen bulbs with projector then it's fine to fit LED bulbs?

No Halogen means it was designed for halogen bulbs, could be reflector or projector type.

Kenai · 12 Jan 2021 at 17:21

Nasher said:
They can't confirm it has LEDs though. One of my cars obviously has retrofit LED sidelight bulbs (they are WAY brighter than halogens), the tester didn't care.

Don't think there are any issues with bulb types outside of headlamps specifically - retrofit LED sidelights don't fall foul of any particular MOT clauses I don't think?

Kenai · 12 Jan 2021 at 17:23

Nasher said:
No external lighting is allowed to be retrofitted.

Don't recall ever seeing such a clause in the test manual but happy to be shown otherwise

Kenai · 12 Jan 2021 at 17:37

Howard said:
Maybe not in a normal reflector enclosure but what about projectors?

It's normally the dodgy looking wiring and ballasts hanging out the back of headlamps that are stamped HCR rather than DCR that gives it away

Kenai · 13 Jan 2021 at 10:17

Nasher said:
No retrofit LED bulbs are. You would have to replace the whole unit for a proper LED one.

Regardless of that being true or not though, it's not checked at MOT, which is why you've never had any issues with LED bulbs at MOT - it's not because your tester doesn't care, it's because the MOT doesn't care.

Headlamps are the only place they're specifically mentioned and that only changed 2 days ago.

Kenai · 13 Jan 2021 at 10:20

Nasher said:
So your first post is fake news then?

In what way?

Kenai · 13 Jan 2021 at 10:22

Nasher said:
But E marks apply to every external bulb. It should fail but it wont.

MOTs don't check for E Marks and none of the test criteria require any bulbs except the headlights to be checked for being the 'incorrect type' that I can see?

There's no reason an LED sidelight, as per your original example, should fail an MOT.

That's not necessarily the same thing as being road legal or not.