Quote Originally Posted by paul ron View Post
Sounds like the head is tripping the GFI, either throwing a spike or a dead short. Check the head for shorts in the plug, the fan, the lamp.

And yes try it in a regular non-GFI outlet.

I hope you'll let us know how this turns out?
What causes a GFI to trip is an imbalance between the hot and neutral. The assumption being that power is flowing out but not returning through the proper route, and possibly through you.

Check if your neutral and ground are shorted in the head. Or if neutral is open in the head. These would allow the device to "work" on a regular outlet, but trip a GFI.