The evaporative cooler is an ingeniously simple machine. It allows the average homeowner the opportunity to handle the routine maintenance of the unit on his own. You may find that the motor on your evaporative cooler needs replacing. If so, there are easy steps that you can do to replace and install a new motor in under an hour.
Take off the bolts on the old motor that are used to adjust the tension on the belt. Remove the belt, and inspect it for wear. You may want to take this opportunity to replace the belt, as well.
Remove the bolt holding the motor pulley, and pull the pulley off the motor.
Remove the bolts from the brackets that attach the motor to the cooler. Your motor will be held in by these brackets, which may swing in an arc, or slide on a track. This movement allows for the adjustment of the belt tension.
Attach the new motor to the brackets with the bolts, and fasten securely.
Slide the motor pulley on to the new motor shaft. Before tightening the bolts for the pulley, make sure that the motor pulley is in direct alignment with the blower pulley, so that the belt will track correctly when turning. Once aligned, tighten the bolts securely.
Slide the belt over both the motor pulley and the blower pulley. Lift the motor along the tracks or slots to increase the tension on the belt. The belt should be at a tension that allows you to push on the midpoint between the pulleys and have the belt move about 1 inch. Once properly adjusted, tighten the bolts to lock the motor in this position.
Refer to the instructions for the new motor to correctly wire it. This is usually a matter of attaching the wires in the same manner as the old motor. You have now successfully installed a new evaporative motor.