So I am just asking, since i don't know, and can't see where anyone said. But how does it disengage when locked? Is there a possibility that it is in the "locked" position? Or is there a setting which has to be done at first, upon initial install?
The clutch that engages the regulator is always in contact. What disengages when the key is rotated to the "locked" position is on the lock cylinder. It retracts a pawl that is normally what drives the clutch when the crank is turned. With it pulled in, the crank spins but won't turn the regulator. When the key is rotated to the "unlocked" position, the pawl pops up and catches on the inside of the clutch, allowing it to turn the regulator.
The difference is not in the width, but how deep the regulator bolts into the tailgate. The Sub regulator probably bolts in further away from the outer panel requiring the regulator to have a longer part where the clutch drives it than the Blazer. Putting in a Blazer regulator in a Sub location and it's probably not going to reach the clutch.
