Hello I have a 2008 XC90 and during a current Ice storm I started my car to warm.it.up and clear the windshield, the wipers will not work. When I turn them on I can hear the motor make a humming noise and I can pull up on the wiper with my hands and they will make one swipe. When they return to home position they will hum again until I pull up on them. Is this a motor issue? Or could something be frozen and they work when warmer?

 

If the wipers were frozen to the windshield and were turned on - The nuts holding the wiper arms to the knurled shaft could be loose. Flip up the plastic cover and tighten with a 13mm wrench (with wiper motor and blades parked in the correct position). If that's not the problem you have to remove the panel between the windshield and the hood to get to the wiper assembly.