PW is setup much like wiper motors. Current limiting power supply so that it does not burn out or blow a fuse at rotor lock. Torque spec is a safety issue (heads, hands, dogs, mcdonalds bags, whatever) as well as have enough power to deal with snow, ice buildup, mechanical drag, etc. Some PW switches are double contact: light touch for 1 feature, push all the way down for the other. Others might be programmable.

The days of the PW switch connected to the motor are long over, the switch tells a computer it wants to run the motor. The computer takes a look around & decides to run or not.

The wiper is a safety critical part so a failure usually defaults to low speed operation only no variable or hi-speed ability.