Hello everyone, excuse my English I use the translator, my doubt is that yesterday I mounted the OEM led taillights on my MK4 and discovered that only the trunk drl works I tried with the forscan, change to led, but we can not turn them on, it only works as the brake light in position ... any way to fix it? 

 

I have read about cutting and splicing cables, but if I did not cut anything, better hehe 

 

I have this lamps by factory. And this is my config. I deeply analysed wirings and there is nothing different with wiring. However, wiring diagrams show wires which are not mounted in real and says nothing about it. So, you may miss some wires. Would be useful, if you deeply look at connector and see if it is fitted with all wires.

OK, I figure it out. The bulb lamps uses one "single strip" bulb for stop and position (naming in posts DRL but this is wrong, it is "position" or "park"). Intensity of this bulb is adjusted by voltage/PWM method. Therefore, there is no a separate position wire in this lamps. This is missing.

So, you need drag this line to the connectors of external lamps.

This is external lamps connector (similar left&right), pin #2 is probably empty:

This is tailgate lamp connector:

There is how it should be connected:

RH: S306 to C415#2    

LH: S341 to C412#2

 

Ford is saving like crazy. Probably you don't have S306&S341 neither pins in connectors C412 and C415. You  need to buy similar connectors and fit in missing pins. You also need to make wires from appropriate pins of C410 to C412&C415. Dragging wires from C410 is the easiest way. C410 is on the right side:

Wire for left side you need to drag somehow from right to left.

And then - Forscan.

This will be useful:

Good luck!

 

 

 

Why there needs to be also wires from C410 going to the outer lightunits (C412 and C415)? Where is C410 connected to?

Cant you just connect pins 2 from the outer units with pins 3 at the inner units?

Does this help?

https://www.fordownersclub.com/forums/topic/111425-2018-mk4-focus-rear-light-upgrade/

2 hours ago, tomo2001 said:

Does this help?

https://www.fordownersclub.com/forums/topic/111425-2018-mk4-focus-rear-light-upgrade/

No this is just the NOOB solution. I know you can connect position 2 and 3 together by splicing and twisting wires together. I was looking into the OEM connections and was wondering what C410 does.