Clam Shell window motor problem

I bought a new motor for a '76 Caprice Clamshell wagon. The motor works but the window doesn't go down all the way. Any advice?

 

Get a straight on shot looks like the door isn't all the way up, but cannot tell by that angle

 

Do you think that might be the issue in regards to the window not going down? I know that there is a mechanism somewhere that prevents the window doing down when the tailgate is down for safety.

 

If the door is not shut completely the window will never be shut. That is what it "shuts" on at the bottom. The angle of the pic you have does not give us a good enough straight on look at the situation to be honest.

 

This is how far the window should go down:



And a closer shot of how far up the tailgate should be (on both sides):



I personally like to raise the window 2" or so, raise the tailgate fully, then lower the glass to make it seal. You can do both at once but that method ensures that the least stress is applied when you're closing everything and verifies if the tailgate won't fully operate it is because of the tailgate itself. The interlock for keeping it from opening was on the manual tailgate wagons (window had to be raised 3" or so to allow the tailgate to drop down). The electric lower tailgate can be fully opened and closed without moving the glass.

 

^^^^^ What he said
Right on the money

 

Thanks for the advice. There was a hose/tube of some sort caught up inside. I removed it and the window came down. I still don't have the window officially hooked up to the cable.
It was removed and I don't know how to get it hooked back up. Is there a manual I can download?