[BiOhAzArD]

The button at the bottom of the B-pillar to turn off the interior alarm sensors is not lighting up.
The red ambient background light works, but pushing the button does not light up the led in the top left corner.

Would this be caused by anothing other than a faulty switch?

 

[Passat2.8]

Here in the U.S. interior monitoring was never an option; fortunately for you I have retrofitted it into my car and know the wiring.

From the factory diagrams, that LED is not shown as being wired in, but I placed a diode in the empty pin to enable it when depressed.

Has it ever lit up for you? If it has in the past then one of the diodes may have went bad-if it is the internal one the switch will have to be replaced.

 

[BiOhAzArD]

No I never saw it lit up before. I've had the car nearly 5 years. What would be the point of the led if it wasn't going to be wired in? :crazy:
The button is a 'click', not a toggle switch (down when on and up when off), so with no led how would i know when the interior sensors are off?

 

[Passat2.8]

The LED would just light up when the button is pressed, then turn off once you let go. Once the button is pressed, the sensors are de-activated when the alarm is armed for only that one time. They will re-activate the next time you arm the alarm after that.

It is an odd design I know, but that's the way they had it. If you want it to light up I can show you how though.

 

[BiOhAzArD]

never seen it light up. I pressed it loads of times in the dark and the little led never lit.

@Passat2.8 If it did light briefly on the press as you say, that would make sense. but it never has.

Faulty switch.? or am I missing a trick here :wrench:

 

[Passat2.8]

From the factory, there is a blank pin in the connector for the switch. That pin is what activates the LED when pressed.
For some reason they never gave it a purpose when they wired up the cars.

 

[BiOhAzArD]

so there may be nothing wrong with it??

I might just arm the alarm and sit on the back seat, wait a while and try set one of the sensor off. see what happens. play around with it.

i'll reply what happens..