I recently bought a 1997 Chevy Blazer LT, everything on it is pretty much mint condition except the Wiper blade which doesn't seem to be working properly. It does move a little but usually gets stuck at some point on the window. If you help it a long a bit while its on it trys to go back and forth on the window but usually just stops or gets stuck at some point.

Is it likely the motor that is bad or something else?

 

Unless there is something you can see physically that is hanging the blade up while it is in motion, my money is on the motor.

 

Do you hear any clicking sounds? You'd know it if it was. It is possible that the shaft that passes through a sleeve from inside of the vehicle to the outside of the vehicle is hanging up (corrosion, rust). You can take the gear box apart and clean the shaft, relube it and re-assemble it. Not too bad of a job. The motor, too, could be flaky, of course. That's easy enough to test though by removing it and putting power to the contacts. It'll run or not. Good Luck.

Another thing: The plastic gears could be stripped inside the gear box (if it doesn't click).

 

I have this same issue...

The shaft tends to rust and cause it to stick, which in turn causes the crappy plastic gear to strip a tooth or two.

Pulling it apart and re-lubing it will help if the gear isn't stripped. If the gear is stripped, you will need a new motor. I haven't seen the $0.27 plastic gear for sale on it's own.

 

Just do what i did,after my wiper "tried" to do it's wiping duties,and stopped midway..replace the entire unit($80)
- lower tailgate,remove 2edge phillipe screws,remove both handle screws,Gentlypull panel off there clips
-remove the 11/12 7mm screws,take off wiper assembly,unbolt 3 10mm wiper housing and assemble in reverse.