Controlling Window Motor

[jhellr13]

We are using a windows motor to control our arm. We want to set it so the arm can go up to maximum height and will not allow the arm to go up anymore. Also, when the arm is at lowest height, the arm cannot move down anymore. The window motor is controlled by a spike relay, thus we are pretty sure we cannot use a servo to control angles and such of the motor. What are some ways we can make our arm act in such fashion? Is their a way to make the motor run for let's say 3 seconds, stop, then reverse for 3 seconds?

Thanks in advance