it's a 1982 suburban and the passanger door window won't go all the way up or all the way down. It 'kinda' grinds right in the middle. Owner said there might be somthing stuck. I'm trying to see if I can get a free manual or some plain instructions on how the mechanism works. Thank you in advance... I live in a really bad part of town and I really don't want the neighborhood kids getting inside. Please help!