All the little copper pads on the one end of the motor have small gap between them.
When the brushes and copper wear down the material builds up in this gap. This causes moderate shorting between each pole of the motor making it run slow.
When you clean the copper you also scrape the black brush carbon from the slots.
When done doing this with a toothpick you will find the edges of the copper are sharp, so you chamfer these edges of the copper so that it doesn't shave the motor brushes down prematurely. If you don't, all that material that shaves from the brushes fills the gap and problem is back very soon.

 

I got my replacement motor from autozone, Its been working great for over a year now.

 

i fixed mine a couple of days back, the new motor was $149.99 at Autozone.. and it was an easy install.. they charge you a $40 fee too.. which you get back when you return your old motor. I gave them my old motor and he thought i was returning the new motor i purchased so i got my motor for free.. haha

 

that's some shady ****. some poor soul might end up buying that **** and throwing it in their Z now ;/

 

or they might just send it back and get it refurbrished if they find out..

 

+1.. it's sad how some people seem inherently shady.. especially over something only $150. I wonder what he'd do for a Klondike bar.

 

WWJDFAKB?

 

t shirt idea!

for anyone attempting this, there are 3 bolts on your window motor that feel like they are made out of ****ing putty. be careful, they strip easily.