I have a 2018 Fiesta Vignale with standard factory halogen low beam headlights.

I've successfully swapped these with a pair of LED low beam headlights which come standard with the 2020 model year onward Fiestas. The swap itself has was straightforward and required no extra work other than literally swapping.

Only thing I've noticed however is that the LED low beam light is slightly brighter when the engine is off. When the engine is started, after a few seconds the output from the low beams drops slightly. I'm thinking this is probably normal, but thought I'd check on here if anyone else has noticed this. I'm interested to hear if this also happens for those of you who had them fitted from factory, or if this is down to me swapping from halogen to LED.

I've had a check through the relevant modules in Forscan but there doesn't appear to be anything relevant that can be configured.

Thanks in advance

The only thing I can think of is that as these have been converted to LED there is a small delay in them gaining full power when the engine is started. 

They may be brighter when the engine is off as due to them being LED they will need less power to produce the same amount of brightness, as your car is expecting halogen it is supplying halogen levels of power when engine is off. As LEDs need less power they would shine brighter.

Hope this helps 🙂

 

(May be wrong as this is not my strong point)

Um, no. That is not how electricity works.

19 hours ago, FocusGeorge said:

I have a 2018 Fiesta Vignale with standard factory halogen low beam headlights.

I've successfully swapped these with a pair of LED low beam headlights which come standard with the 2020 model year onward Fiestas. The swap itself has was straightforward and required no extra work other than literally swapping.

Only thing I've noticed however is that the LED low beam light is slightly brighter when the engine is off. When the engine is started, after a few seconds the output from the low beams drops slightly. I'm thinking this is probably normal, but thought I'd check on here if anyone else has noticed this. I'm interested to hear if this also happens for those of you who had them fitted from factory, or if this is down to me swapping from halogen to LED.

I've had a check through the relevant modules in Forscan but there doesn't appear to be anything relevant that can be configured.

Thanks in advance

That's a fantastic result, thanks for sharing.

How does the levelling work?

The current MY Fiesta only has LED daytime running lights and LED Low Beam within a projector housing without any self levelling as standard fitment.

The full LED optional set-up includes levelling. 

So the manual levelling control on the dashboard still works OK with the replaced units?

Please could you post the correct part numbers for these led low beam units?

 

8 hours ago, Jonson said:

So the manual levelling control on the dashboard still works OK with the replaced units?

Please could you post the correct part numbers for these led low beam units?

Yes correct, it's a plug and play swap with adjustment using the leveling knob. Just remember to correctly align the headlights with via the adjustment screws on the units themselves when you first install them.

The LED low beam unit part numbers start with L1BB (rather than H1BB for the halogen equivalents). Just go on ebay and search 'Fiesta L1BB' and you should find plenty.

21 hours ago, Aldridge Andy said:

The current MY Fiesta only has LED daytime running lights and LED Low Beam within a projector housing without any self levelling as standard fitment.

The full LED optional set-up includes levelling. 

I see you have a 2021 MY Fiesta - have you noticed a slight dimming of the low beam after the engine has started?

@FocusGeorgeI can certainly check when I next drive but at the moment I’m locked up at home with Covid and 8 days until freedom.

Just for clarity, my low beam lights don’t come on until after I’ve started my car thanks to auto headlights. Daytime running lights reduce in brightness as low beam illuminates. This happened on my previous 2018 MK8 with halogen low beam.

So should I expect ( when I pull on to my driveway at night ) the low beam headlights to get slightly brighter as soon as I turn off the engine?

Why does this matter?

On 11/5/2021 at 7:39 PM, Aldridge Andy said:

@FocusGeorgeI can certainly check when I next drive but at the moment I’m locked up at home with Covid and 8 days until freedom.

Just for clarity, my low beam lights don’t come on until after I’ve started my car thanks to auto headlights. Daytime running lights reduce in brightness as low beam illuminates. This happened on my previous 2018 MK8 with halogen low beam.

So should I expect ( when I pull on to my driveway at night ) the low beam headlights to get slightly brighter as soon as I turn off the engine?

No rush at all. You're correct about getting brighter when the engine turns off, again about a second or so after switching engine off the output ramps up slightly. It's perhaps not too noticeable until you know what to look for, then you start to notice it every time (or maybe that's just me!). Same also happens during start/stop while headlights are on - engine stops, lights brighten, engine starts, lights dim.

On 11/5/2021 at 8:20 PM, anon said:

Why does this matter?

Because I would feel more comfortable with the headlight swap if I know it is working as intended. If the brightness reduction is not normal, then it would indicate that the lights are running at a lower brightness than they should which could be a safety issue. If this happens for everyone with these lights, then I can be happy that the swap has been successful.

16 minutes ago, FocusGeorge said:

If the brightness reduction is not normal,

It's normal on almost all moden cars. It's just that with LED headlights which take a lot less current than other types its noticeable.

With the ignition on and the engine running there are a considerable number of circuits live and all drawing power from the cars electrical system. The smart charging system maintains a voltage level necessary to ensure the car runs correctly and also at a level that charges the battery. This voltage can be around 13.2 to 13.8 Volts and is constantly been adjusted by the voltage regulator/smart charging system.

When you bring the car to a stop, the engine revs reduce and the voltage produced by the alternator is reduced and any addtional power that is required for equipment in the car is supplied from the battery. At this point the vehicles system voltage is reduced, typically 13.2V.

Once you switch off the engine the you have removed all addtional loads from the system and the battery voltage recovers and rises to a nominal value of 13.7V. Due to the low current draw of the LED headlights the slight increase in voltage causes the lights to become brrighter for a period of time.

Cars that have for example Halogen headlights have a much higher current load and therefore the lights themselves cause a heavy load on the battery once the engine has stopped and so an increase in voltage (if any) will be minimal.

So after a long answer, its normal, don't worry about it.

@unofix Thanks for your detailed answer - exactly the kind of info I was looking for. It all makes sense and I feel a lot more confident in the swap now. Cheers!

no it's not normal because the car would like 55w halogens while the LEDs absorb 13.2w...so the bcm goes into protection by lowering the intensity... even at it did it to me... in addition to this there was also some flickering... I solved the problem by inserting a 50w resistor deceiving the bcm into having halogens so they don't lower their intensity and work at full capacity. I have one Fiesta mk8 2019 with later addition of 2020 low beam LEDs