Cars with electrically operated windscreen washers sometimes have a switch controlling the motor incorporated within the windscreen-wiper switch. If the motor does not work, check first that the switch is functioning; if it is, check the wiring to the washer motor (See How to test electrical circuits). Read more
The motor and the pump are usually a single unit, the pump being a simple device. If the non-return valve and the hoses are sound, the old motor can simply be bypassed.