We blew the fuse on the front/back accessory plugs in our X a few months ago.
I was surprised to find Tesla didn't provide any documentation on the fuses - something I've had in every other vehicle. When I called Tesla's phone support team, they couldn't provide me documentation on the fuse location, and said I would need to take the car into a Service Center to get the fuse replaced.
There is a fuse box located in the frunk under the cowl. There is a second fuse box located above the pedals under the steering wheel (which is where the accessory plug fuse is located).
Note that getting the fuse replaced at the Service Center (or by a mobile service technician) can be done pretty quickly. Though they'll also likely do an inspection of the car to ensure there isn't a more serious problem that caused the fuse to blow.
In our case, it was a defective Tesla tire pump. We had one of the original pumps purchased for our 2012 S P85, and evidently it failed over time - which ended up blowing the fuse in our X when it was plugged in (ended up replacing it, in addition to the fuse).
