Why would a 1999 Mountaineer rear wiper only work intermittently?

Answer 1

This is actually a really common problem according to my dad who has been a body man for over 40 years. According to him it may be a loose or improperly sized bolt that holds the wiper motor down. I haven't had him try to fix mine yet because it doesn't bother me that much but he thinks that this bolt problem puts the rear wiper in a bind and occasionally won't let the wiper move. I may have him take mine apart and get a better answer I only worry about messing up the rear door interior panel which is very expensive to replace according to my father. I don't know if this helps but hope so. Also don't take it to a Ford dealer because they will turn it on once and if it works they will say "It's working perfectly" and be done with it. To fix the rear wiper: 1) Start the vehicle, 2) Turn the rear wipers on high, 3) go to the back of the truck and pull the wiper out of the stand, 4) push the wiper down until it begins to move (this may take a few times until it senses). I have to do this about every 4-5 months, depending on the road conditions I travel. Seems there is a sensor that gets off from the wiper motor. This should fix your problem