550 Dome/Door light issue

When i switch alarm off on with the remote control box,at the opening the door dome light works.
I think that the problem is with a relay working with the alarm
I made a test of polarity with the door lights and it seems to be inversed.
Gost?

 

Probable cause is oxidised contacts of the door jamb switches, happens pretty quickly in some environments. They can be cleaned and lubricated when removed. Do not unplug them unless you need to, the wire can fall into the door pillar, which will be bad for your mood.

 

The b pillar switch is for the opening of the window when you open the door.
One moment i thought it was easy like this..

 

On the 456 the switch that sits invisibly within the catch on the door is for the window, while the switch under the rubber "donut" in the jamb controls the dome light. I looked in the parts pictures and while I can find that dome light switch in the 456 pictures, I cannot find it for the 550. I am pretty sure the 550 should/would be the same, unless the Italians combined the dome light with the switch in the lock catch on the 550/575 family.

 

For the 456M there is no switch on the door jamb for the dome light.
For the 456 maybe it is like you say.