When I turn the nob it tries to go up but just falls back down and when it does go up (10% of the time) it barely wipes anything.
If there's a spring in the wiper are it may have a bunch of stuff in it from the road causing the issue where it's not hitting the window. Sometimes if you work the arm back and forth a little they will free up. On the other issue where the arm goes up and falls, remove the wiper are from the stud an check to see if it's stripped.You might need a new wiper arm if it is.
You have to remove the trans to do it.If you're not experienced and have the proper trans jacks I wouldn't suggest trying to do it yourself.Besides the fact that you could damage the trans which is expensive,you can seriously injure yourself if the trans slips and falls.Take it to a transmission shop and have it done right.
It sounds like you need a new motor for the rear windshield wiper. You can purchase these sometimes at junk yards or always at a Ford dealer. The motor is located inside the back lift door and it can be user replaced.
If it trying to work the motor is ok it could be that the motor drive shaft is loose ,remove the wiper arm and try to tighten up the nut what you will find under the wiper arm . I hope this helps you.
