Hey, I got the same experience before, what I do is find another piece of copper plate and soldered it to the existing "shortened" copper contact. At the same time I clean out the grease and replaced with electrical contact grease. And it work, but for a few months only. The soldering is not that good.
Got myself a used one from chop shop for RM90. Before installing it, I clean the existing grease and replace with a new grease. Working till today.
Just want to share the experience.....
But be carefull when you buying from the chop shop, make sure it is the exact one. What I mean, my wiper motor located on the left side and the first attemp I bought the one that are located on the right side. Both are exactly but are like a mirror image. I wasted more than 3 hours just to dismantled it and went back to the chop shop to change it again. Luckly they got it.