Ok, we just switched the connectors (above the extrusion head). The side fans seem to be connected with green-green and yellow-green wires. After switching the connectors of the left and right fan we now have the left fan working but not the right fan so at least we now know that both fans are working... they only work when connected to the yellow-green connector so there seems to be a problem with the green-green connector any ideas of what might be the problem ?
Robert: We're using the UM robot and the fans start right after the first layer. Also, i did not find an option to turn on the fans in the tuning menu, i can only control the speed.
Thank you all for the support! We're looking forward to having this sorted out so we can start doing some cool prints