well im not sure on a manual for that big of a window if you still cant get it working hmm id use like the same concept out of like a front window pretty much like siscor method i dunt know if a regualr manual window crank would hold the big of a piece of glass also think about trying to crank that thing up its pretty heavy for say a normal manual crank arm but i have seen a full universal kit at auto zone for not that much they also have the auto to its not that expensive you just got to have some time and be a little creative but before doing all that take the motor out and put 12volts to it see if it is that it might just be some small simple thing and could save you alot of work if it doesnt work perhaps find a jumer doesnt even ahve to be a sub theres some 90s SUV's that have them i think the bronco also has it junkyard it till you find a good one