Roof light in the cargo room


As topic says, roof light and cargo room. My T6 Transporter has the two lamps in the roof and they are connected with three wires and they dim down when inactive, starting engine, looking etc. And I want to place some more light in the cargo room because of the Sortimo layout I have in the van.

So now comes the issue, one of the wires is negative (Ov), one is positive (+12V) and the third is unkonwn to me. LED strips from china will only be ON, and they dont shut down what ever Im doing. So since Im an electrician this means that this should be solvable for me, but im not sure what VW has made here.

Is there a dimmer module and that the LED´s need to be a special kind?


Senior Member
You have positive supply, negative supply and a switched negative supply via doors, sounds like you have connected to permanent negative instead of switched negative


Auto Electrician
Trade Member
T6 Legend
If you fit LEDs to this circuit chances are that they will never go off completely. Bulb monitoring circuitry passes a small current through the circuit but it's enough to put the LEDs on.


Alrigthy then. Is the electrical setup pretty similar to the T5? Or has VW made some major changes.
I guess that a cheep LED strip from china has some limitations.

I have aftermaket LED roof lights mounted and they dim down and goes off when they are supposed to, and they are connected with the tri-pin plug.

Note to self and others. Be careful when using the multimeter pins to measure, its easy to blow fuses if you aren´t careful..


It works!
There is three wires, Red,Yellow and black

Red is +12V
Black us 0V
Yellow is switched 0V

So when connected to Red and Yellow it works perfectly. Led strips dim down also.


Funny thing is that the LED strip i got from China said to be white, but is bluish in color. Looks weird and wrong so a new strip is needed to get the propper look. I will post a picture later.

Its good space above the inner roof to pull cables for stuff..