There is a long spring below the coil that is detached and I don't know where it should be hooked; the other end of this spring is wrapped around the small rod that holds the ratchet. I'm assuming this spring pulls the plunger out of the coil so that the ratchet grabs the next tooth on the plastic sprocket and then, when energized, the coil pulls the plunger back in. This is NOT the spring that opens/closes the side door.
Can't tell from the pictures. Put the mechanism down and take multiple pictures of the entire mechanism from the sides, top, whatever can be used to identify the spring and it's mounting.
Did my best with lighting to take better pics. As you can see from image 6386, one end of the long spring is detached; it points towards the rear of the coil but I'm not convinced it attaches at this end. I'm thinking the spring should attach in front of the coil to pull back the plunger when the power is turned off --- but I'm not sure.
On my car the long torsion spring is wrapped around the brass rod that supports the ratchet. It goes down in the channel and makes a u turn and comes back up. It ends up on the coil face right next to the coil electrical terminal. Look closely at the attached photo. The photo lost a lot of resulation when it was posted, but the spring is right against the side right wall in the corner.
That was the fix!!! Your photo showed the spring wrapping over the top of the metal plate in front of the coil; there was a small hole in mine in the same area so I placed the hook of the spring in there. Works like a charm!
Quick question - Is the mechanical mechanism in the 3854 the same as the mechanism in the 3454 merchandise car?
Yes it is. The mechanism in the 3854 comes from the 3454 car. There are actually a fair number of parts for the 3454 mechanism still available. It is not easy to work on as everything is either staked or riveted together.