Where I live in upstate new york it is not uncommon for the temperature to stay between 0 and 10. The past few days have been like that and i notice that when I start my car in the morning my rear wiper does not work. continues not to work on the morning commute. If I try it later in the day if the temp gets above 20 or so it works just fine. those who live in cold climates know cold does funny things to cars, im just wondering if anyone has an idea of what could cause this?

Blade frozen to the window.

 

give it a lift and tap before trying it in the mornings.

Its not frozen to the window, i make sure to lift the wiper and clear off any ice. The wiper blade moves just fine, a little bit of play in the linkage. I can hear the motor working, too.

pginter96,

 

These rear wiper motors have a cast aluminum/pot/white metal casing with a steel drive shaft. Over time with salt and water and electrolisis the two metals corrode and the shaft seizes where it exits the casing. Yours sounds as its about to seize solidly due to the extreme cold temperatures, but later as the day warms up a bit it finally has enough clearance to free its self.

 

I would pop the plastic cap off the wiper arm at the drive shaft, remove the 10 or 12 mm nut and pry the wiper arm off the shaft. Then fire some 3 in 1 oil or similar on the shaft and turn the motor on and add more oil. You'll most likely see much better performance.

 

Unfortunately, like your emergency brake, use it or lose it. Lack of use allows for the parts to seize up.

 

If you are inclined, pull the motor from the tailgate (its not hard to do). Once on the work bench drill out the rivets that hold the case together and pry the halves apart. A total clean up of the interior parts with new grease will make a huge difference. Simply put the motor back together again with machine screws and nuts. Good Luck!

WHat pginter96 said.