Alright, I disassembled everything, and it would appear that I don't have the same setup as in the link you posted, Keith. Here are a couple pics of the linkage and motor assembly, I removed the whole thing from the car so I could figure it out, fix it, and put it all back together. . .
I don't see any "stop mechanism" or cam in there, it looks like it either never existed there, or it was removed.