DRL headlamp issue

[Sparkman]

Hi , new member here , asking a question which seems to be a common problem for the MK7 2016 Fiesta ST. The offside LED strip has a will of it's own, sometimes it comes on, sometimes it doesn't, I can only describe it as when it does work you can be driving down the road and it turns itself off ( I watch it from the reflection of the car in front of me). other times I can have dipped beam on with both LED's working and roll it into the garage only to turn off the lights by the switch and it flicks off nearside staying on. when I turn off the engine and exit the car both lights come without fail until I lock it and both go out as they should. Any ideas as to the root cause? I don't want to go to the expense of buying a new headlamp to find out the problem is elsewhere. Thanks in advance.

 

[kimsdad]

Welcome aboard. The fact that you mentioned it stays on after exiting the car but goes out when you lock it suggests the LED driver is failing when the engine is running and is under load.

Locate the LED driver module on the back of the problematic headlight and inspect it for any signs of heat damage, such as discoloration or melted plastic. If you find damage, replace the driver module. This is a much cheaper repair than buying a whole new headlight assembly.