Mine are just really slow, but it's only when the X is first started up. After the alternator juices the batteries back up, all is well.
I would definitely say that it's the 2nd half of the window rolling down that takes the longest. Don't try to roll down more than one window at a time, it takes quite a while. I like to "race" mine and see which one wins. The rears are always down before the fronts. The power windows draw quite a bit of juice.
My auto-down feature has never stopped mid-way through rolling the window down, it always opens it completely.
Just noticed this post. I had this problem (drivers door), so I pulled the inner panel to see what's up. Turns out the runner the window slides down in is narrower at the bottom. Any junk at all causes the track to become sticky as it loads up with crap. Wiped it off with a cloth, then sprayed window lubricant (silicone spray'll work too) into the track, now everything's fine.
Score another brain fart on the design engineers part.
my drivers window will stop dead about 2/3 down without a little help from my hand. Doing this for 5 years, guess I'll clean the tracks out. It will go down ( but slowly ) all the way only if the drivers doors been sitting in HOT direct sunlight though. Thanks I almost bought a new regulator and motor on ebay because it just started to bother me enough to fix it.
1973 K5 Blazer 383stroker,TrickFlow alum.heads,Crower forged rods-roller lifter cam-roller rockers,Keith Black10.5:1,Doug Thorley tri-y,MSD,ARP,Q-jet,on 1 ton axles,1991 front clip,3K miles on FULL body off rebuild