Hello,
So far progressing on getting this fixxer upper ducati going. Now to tackle the brake light. it works from the front switch however the lever doesnt make contact with the switch sensor, is there a screw or something that went between it? because the sensor switch is very shallow..
Stock rearsets/levers had a screw with a smooth button head on it. There was a small (~2.5mm) hex in the end of the screw and a nut used to lock it in place once adjustment had been made.
That said, the switch is a normally closed unit which means if the screw is missing and the switch plunger isn’t being pressed in, contact is made and the brake lamp filament will light up.
Disconnect switch. With key on jump the two wires going into the harness. Bulb lights? Bad switch or connection. To confirm the switch is bad, with an ohmmeter check the switch. As Portu-Guy said, normally closed, so you should see continuity.