This has nothing to do with this forum but you guys seem very knowledgeable! 90 Lincoln wipers don't park anymore. They park straight up instead of down. It seems to be a common problem with TC, Grand Marquis and Crown Vics. Any suggestions? They work in all modes just fine except when they park.

 

The park switch is in the motor. I have always replaced the motor to fix this.

 

Fixed! It was the aluminum part that drives the arms. When the motor reverses to park, this part rides against a steel pin that catches and pulls it in to park position. When it catches it causes the shaft to pull a spring loaded pin and rotate 180 degrees to pull the blades to park. The steel had worn the aluminum where it wouldn't catch. Sharpenining the edge with a dremel tool fixed it. Lots of time little money.