I bought a rebuilt wiper motor for my 89. When I went to install the crank arm on the new armature I saw that the machined groves in the end of the armature that prevent the crank arm from spinning were horizontal and not vertical. If I install it this way the crank arm this way, it will be 90 degrees off. The armature doesn't rotate by hand. Is the position set by powering the motor or do I have a motor that was assembled incorrectly?