fairly simple you just have to follow things
to get the motor turning live enters at the top. It goes to terminal 3 on the switch and goes through contact A7. it leave the switch on contact 3a. one wire goes to the thermostat and on to the element. since the element is working we can say that up to this point all is ok
the live then links to terminal 4A. it then goes through A7. leaves the switch on contact 4 and goes to the motor
then neutral is on the same supply as the element so i cant see any problem there
so you fault is either contact A7 or the motor
Dave