Wiper blades stop in up position on 1999 Grand Marquis

This is usually a contact inside the wiper motor. Some are accessible and some require replacing the wiper motor. The inside of the wiper motor jumps into a derailer which breaks the electric contact that keeps the motor turning. Once the motor cycles, it parks in the down position.

The insides of the wiper motor are suppose to coast without power into the Park position.

We have the same problem on our 97 Grand Marquis. We have replaced the wiper blades and the drivers wiper arm with a used one. The problem was not completely solved but it did work better. We are going to replace the arm with a new one and see if that works better.

try this fix
remove wiper arms from where they connect on car
turn wiper moter on then off. turn ignition off
if wiper motor is good it should put spline in off position and now all you need to do is replace wiper arms in the correct position they would be in when wipers are turned off

needs wiper module. check bushings around wiper motor at the firewall.

Intermittent wiper control stopped working on my 1996 GM last spring. I ended up replacing the wiper motor ($100.00 part). Since I have found it on Amazon for $58 including shipping. It works fine now. Only bad part was all the "stuff" that has to come out (like dead leaves!) to get to the wiper motor. Also make sure you have your wipers in the down position when you replace the motor.
Hutch50

this is a very common problem on these vehicles. the wiper motor has a park switch built into it that fails. replace the wiper motor and this will stop problem. hope this info helps you!

go to link

http://www.streakfreewiperblades.com/site/990209/page/561743

wiper motor bad

You will need to replace the wiper transmission.This is a common problem.