Crown Vic: Window shield wipers turn on by themselves.

Use vinegar to unfreeze

The wiper motor is under the black plastic cowling below the wiper arms.

Hello, Its the Multifunction switch for the turn lever and wiper controls. The contact points are usually corroded or loose and a bump can cause them to make contact. The usual solution is to replace the switch. Only a few styles are capable of being cleaned and disassembled.

You will need to remove the steering column cover. Usually requires moving tilt wheel several times to guide plastic cover out of place. There are 2 wiring harnesses attached to the control. They have flimsy latches and care needs to be taken when spreading the latches or they will break.
The switch has several torx head screws or in some cases Security screws holding the part to the column.

There are differences in the number of contact terminals in the switch. Some have 2 additional posts for other functions. Best to bring in old one to get correct part.

the linkage between the wiper motor and the wiper arms needs to be replaced. the stud on the one side is stripped and that is why it doesn't work as it should. this happens usually when the wipers are left on in the winter with the blades freezing to the windsheild. turn on the car with frozen blades tends to strip out the teeth holding the wiper arms onto the linkage

WHERE THE WIPER ARM AND SHAFT COME TOGHER THERE IS A LEVER LIFT UP THE WIPER SO THAT IT IS POINTING AT THE SLY AND PRY OUT THE LOCK AT THE BASE OF THE WIPER ARM .

I replaced the same part on a 1994 Crown Vic. There are a few bolts which go through rubber mounts on the firewall and that is how the wiper motor fits against the firewall. There is a clip on the wiper drive that must be pressed and slid off the wiper shaft. The hardest part was getting clearence between the engine and wiper motor. If I remember there was a way to turn the wiper case to clear the engine. I have asked myself why this was engineered like this? There is nothing important in the way that 3/4" of clearance could have been given for removal.

Run a small wire into the nozzle to clean it out

Hmmmm... if you replaced the motor you must have cleaned the area housing the arm mechanism. I had the same problem and found the problem to be in the arm assembly box on the firewall. Under the hood, triangular shaped box with snap on top was full of dirt, leaves and pine needles... I removed all the **** & my wipers now park as they should!!

Fuse no. 7(10amp) in interior fuse panel and fuse no.110 (30amp) in underhood fuse panel

It's probably going to be the switch arm itself.

The part is a bit pricey, but it does come with the wiring diagram to place the new one in there.

The switch is the whole thing, turn signal, wipers, etc, and the arm.