There are 2 fuses (green ) in the black box of fuses/relays on the n/s inner wing in the engine compartment.1 of these fuses is for the fans.It is partially hidden by the wiring loom so not obvious at first glance.I would check this first.Fan motor can be tested by unplugging connector near the fan motor and running 2 wires from the battery terminals directly to the connector - it would be good practice to have an inline fuse in the positive wire.

Testing fan switch,in the absence of a known good one to swap it with,I guess some sort of continuity test,bet Im no expert with electrickery.
Dont work on the cooling system while its hot if you can avoid it,very painful burns can easily be the end result.

Running the engine at 100 plus degrees could easily cause serious damage to the engine,I would stop using it until its sorted if I were you.

wont be a thermostat problem,thermostat not connected to fans,and I believe the thermostat normally sticks open if it fails which would cause the opposite problem to yours.
