My rear wiper stopped working after winter. I recall turning it on when there was a chunk of ice built up on the rear windshield and it stopped working since then. Is this from the mechanism intrinsic to the wiper and its attachment or perhaps a coincidental electrical failure?
Personally I believe in cause and effect. Whatever happened during the winter caused the wiper to stop working. Have a good independent mechanic look at it.
The wiper arm splines may have been stripped out when the wiper was frozen to the rear window.
Every winter, I see people turning their wipers on while there is ice or a huge amount of snow on the window, and–inevitably–many of them wind-up stripping the splines.