During ‘on’ time of spin direction timer IC2, the output of negative- edge triggerd JK flip-flop at pin 2 goes low to energise relay RL2 and washing machine motor rotates in one direction. During the off time of IC2, the output of N1 goes high again to de-energise relay RL1, which cuts off the mains supply to RL2 and the monitor stop rotating. Floating point trouble may occur at trigger pin 2 of IC1. Resister R8 over comes this problem by holding pin 2 high.
Remove the adjustment mechanism it's often part of the bracket holding the switch in place! As for identifying the pressure switch, that's easy. Nine times out of 10, it's directly behind the 'water level' adjustment knob in the top control panel of the machine. If the machine's upside down or partly destroyed, follow the sensing tube from the base of the wash tub. And while you're at it, it's also usually worth scrounging the tube, which is often a high-quality plastic hose. You never know when it might come in handy.By contrast, dishwasher pressure switches are normally buried beneath the stainless steel drum.