Send Help (and Maybe an Exorcist): Truck Loading Nightmare.

The plan:
I want to load the green truck onto the yellow truck's trailer because they're both headed to the same destination.

What I've tried:
I've backed the truck up to the end of the trailer to pull it up.
I've pulled the truck up the end of the trailer to pull it up.
I've tried pulling the truck onto the trailer from the side.

Where I need help:
Why does the truck try to drive when I winch it regardless of its running status?
Why does the truck turn hard left when I try to pull it with a crane?
Why does the truck roll right off the edge of the trailer if I do manage to get it up there (on a flat surface)