How do I wire a pull cord ceiling switch?
The fan switch is a three pole switch - basically three switches that operate at once.

The switch should have two sets of three terminals, labelled L1, L2, and N, plus earth terminal(s). Connect one red wire to each L1 terminal, one yellow wire (with the red sleeve) to each L2 terminal, one blue wire to each N terminal, and the earth wire(s) to the earth terminal. 

The yellow wires with the red sleeve is the switched live from the light switch, which turns the fan on. The red wire provides the permanent live to allow the fan to run on for a period when the light is turned off.