I built my eGPU setup with an Akitio thunder 2 and a Zotac gtx 970 a few weeks ago. It worked pretty well, but the fans of the eGPU doesn't change speed, neither under high usage... I heard about zotac firestorm and other drivers that can control the fan´s speed, but I want to keep OS X and don't want to change to windows... So I opened the case checked with a multimeter how high or low the voltage of the fans are, but somehow I touched with both poles of the fans and the whole setup shut down. I rebooted it and the eGPU worked fine, but the fans doesn't move ant all... I disconnected them and powered them separately and they spin! That means that it could only be a software problem.
I hope you can help me