Peugeot 206 speedometer stops and engine cuts off

Hello a new post From mine, the problem is the car drives smoothly but once its heated the fans turns on and cools the engine and after that the speedometer comes to halt and the engine cuts off. it will start like nothing has happened. but the speedometer wont be functional.have to park the car and after few mins the it will be solved. This happen only after the car fan has been operated to keep the engine to running temperature. Hope someone will have enof idea to save me from being over charged THANK YOU =)