if the park function is the only problem and your going to throw out the motor any way, you can repair it
the switch is like a set of points where the cam is always rotating on the point arm
the cam eventually wears thru the arm causing the switch to work intermittently
i have fixed the arm before by silver soldering a piece of copper to reinforce the arm
you'll need to drill out the rivets that hold the motor together and then screw or glue the housing back together
easy peasy
