I think I connected it the right way.Pin 2 ist connected to 2/13 of the relais and GND is connected to 6/9. Then I switch Pin 2 between low and high every second but nothing happens.
oh, that works. What could be the problem?
Ok, new findings If I connect the relay manually to 5V the relay doesn't switch but the whole Arduino gets switched off. So it seems to suck too much power?!
hm, thought it should be right but the schematic seems to be the other way round than I thought. Now everything is working So the problem was:1. Relay connected the wring way2. pinMode to Output forgottenBig thanks to all of you!