It sounds like a short circuit in the control switch. The quickest, easiest and cheapest way to fix it would be to pull the fuse that controls the rear wiper.
Because the windshield wiper is on.
How do you replace the windsshield wiper relay in a 2004 Ford Focus. It would appear that the relay is in the fusebox, but access to it is impossible. Looks like the fusebox may need to be removed to access.
Fuse or windshield wiper motor.
a bad fuse, control module (that little thing you use to turn on your wipers), or the windshield wiper motor is bad.
I would call them a nozzles.
I have a 2006 Ford Focus (Australian model). You would think changing the wiper rubber would be a piece of cake, wouldn't you? Not so. Here is how: http://www.madram.net/madram/pageDisplay.php?module=page&pid=46
If windshield wipers are stuck in position and won't move, I would say that the windshield wiper motor needs replacing. This happened to me last year.
Check linkage first and stripped or loose wiper arm on spindle.
a blown fuse.
It may be due to a broken linkage.
Your wiper arms that run from the wiper motor to the windshield wipers may be binding and need to be replaced
I would start with testing the "park" switch inside the cover of the windshield wiper motor.