2000 C230K Windshield Wiper Malfunction

[cehvinn33]

Several weeks ago, my windshield wipers started getting stuck in certain spots. Whenever it rained hard, the rain provided enough lubricant that it wouldn't get stuck. But eventually, the wipers didn't move at all. I found out that they tend to do this and you need to grease them, so I recently used white lithium grease, took off the plastic at the base, and applied the grease.
After I did this, the wiper still doesn't work. However, a couple of times, it did move just a little bit when I turned it on, before getting stuck. I was worried that the motor burned out, but this gave me some hope.
Does anyone know why they still aren't working? The grease says to apply at temps above 50 degrees, but it was probably below 20. Would this cause problems? Please help!!!!