I have 2002 Blazer 4wd LS. Once, the rear wiper did not move when I turned on the switch. I did not hear any noises. I pulled the fuses and left it until I had time to check it. When I got around to checking it I replaced the fuses and turned on the switch. The wiper went up about ¼ of the way and then stopped. I jumped out and pushed it by hand. It then started working but seemed slow. Any ideas? If I wanted to try to lubricate it somehow, where would I start? Inside the tailgate somewhere or outside? What about lubrication for the motor itself, the shaft somewhere or the gears? How are they accessible? Thanks.