Central locking system

[EE80Liftback]

amigaguy Wrote:I just hope the central locking control box doesn't mind getting the 12V input when the door is closed...

It won't. In the control box there's a circuit that needs to flow to ground via the switch, no ground = no flow.

These control boxes are meant to fit most cars and almost all cars ceiling lights work this way. If you would switch off the ceiling light and the light in the boot with their own switches you'll see the 12V has gone and your relay set up won't work any more...