So.. I build a workaround and I think its perfect.. It has been working for 1000km and I think there no problem anymore... My Solution: I buyed an second pressure switch.. the pressure switch is between the relai and ignition+, so I have automatically permanent 8 bar in the air tank.. But when...

Ok.. It's just raining right now.. I hope it will end in the near future

hehe I'm still allive and I will share the solution but I was not home last week and I didn't really have much time last week.. If the weather is okay, I will check all of that tomorrow :):) but first of all thanks to everyone to help me!

hmm.. I can't imagine that, but I will see it when I disassemble the fuse box. But I can only do it on the weekend because I don't have much time this week.

What are the cables for?

yep since 2019

I checked the wire connection between the fuse box and the ECU and I have below 0,5 Ohm, so the connection is good.. :/

wait wait wait there is nothing of that "see/feel/hear the relay operate" EDIT: it's still the same problem that the relay wont start to work

I already done that and nothing happened

oh okay.. Is this difficult to disassemble?

nope which white connectors? HAHA yeah the "gefickt" (in english: "fu ck ed") is absolutely brilliant ;D so you mean it help when I spray PCB Cleaner into the fuse box?

oh yeah that make sense thank you!

thanks ok what is an duff relay, I always associate duff with the Simpsons xD

nope yeah I know that it's ridiculus but yeah I know that problematic

haha good joke ;D so I have an relay tester and the relay works but I have done this before.. and nothing happened