my fan has never turned on and new fan control units are a bit pricey anyone got the steps or which wires i need to connect to a switch so i can just do it manually?

 

The temperature sender unit is near your heel. This shorts to earth when hot enough. So put a switch between earth and this blue wire to turn the fan on manually. If the fan doesn't come on when you short this wire to earth, there is something wrong with the fan control unit. If so, you could disconnect the white/black and pale blue from the control unit and put the switch between these wires. Note, when the fan is on, the blue is an earth and pale blue a live, so don't mix them up.