Unable to turn on bluetooth with Yosemite I can't for the sake of it turn my bluetooth on in Yosemite.
It is greyed out and the menu bar shows bluetooth disabled with a grey wiggle line through it.

Anyone have a solution?
Hopefully you found the solution by now, but I have had this issue numerous times with Yosemite. I have to shutdown the system completely (not a restart) and then it miraculously comes back on. It just shuts off completely for some unknown reason.