Shut off power to the evaporative cooler at the main power panel. Make sure that the green ground wire of the motor is connected to the evaporative cooler ground. Strip one-half inch of insulation off of the end of the black hot wire from the power source. Connect that wire to the hot terminal (L1) of the two-speed switch and tighten the connection with the screwdriver.
Take the red wire from the motor and route it over to the two-speed switch. Strip one-half inch of insulation off of the end of this wire and connect it to the low-speed terminal of the switch.
Take the black wire from the motor and connect it to the high-speed terminal of the switch. The remaining terminal on the switch supplies power to the evaporative cooler pump. Connect the black wire of the pump to this terminal. Connect all of the remaining white neutral wires and bind them together with a plastic twist cap. This completes the switch installation.