Thero fan wiring diagram for 1999 beta techno trials bike

Your master cylinder is most likely a brembo. It will be the same a lot of Ducati (monster, multistrada, super sport), and aprilia's (from 125's to rsv's). They come in black, silver and gold. The color does'nt make them better (just the look). The only difference comes from the piston diameter. It will make it sharper, stronger, more user friendly depending on the size, but for your trial bike, I think any will work well.
Franck

There are a couple of diagrams and a good discussion of this at this link: http://www.2carpros.com/questions/1999-cadillac-deville-cooling-fans-relays - Read in particular the info from expert "FactoryJack" about the 3rd comment down. Good luck!

you have a gasket leak between the head oil/water ports..

It does have a fan switch, it looks like a bolt head with 2 wires on it. It will be on the radiator near the bottom. Connect the 2 wires together to test the switch.