Base points and Links not lining up

[limartin]

I am very new to Revit and got dumped in to this project because I was the only one brave (foolish?) enough to say, "sure!" The project architect has been producing four models that I have been linking into our project "origin to origin". Each model has its own grids and elevations and with each iteration, everything lined up, until the last issue. None of the grids line up, although the elevations do not seem to be affected. When I look at the base points, only one of them is at 0,0,0 and they all seem to be off from true north by different degrees.
Here's the strange part - there is a fifth model that is included in the package, but it does not link to my project without crashing. I open it and it contains only annotations and sheet views, so I usually ignore it. However, if I reload all of the other models into it, their base points snap right to 0,0 and the grids line up perfectly. I cannot reproduce this even if I start with a brand new project. I have searched the boards, the help file, the books and cannot find an answer. What am I missing?
Oh, and I have also tried reloading the fifth model with all of the other models attached and the whole thing crashes. It is not a workable option, anyway because I need to be able to identify which model it is I am working around since they sometimes overlap.

[dhurtubise]

Sounds like Shared Coordinates were established, hence the line up.
That means you will need to use the same Coordinate System. Look up the wiki for Shared Coordinates.

[limartin]

Sounds like Shared Coordinates were established, hence the line up.
That means you will need to use the same Coordinate System. Look up the wiki for Shared Coordinates.

Well, I tried that as well, and got a message that there were no shared coordinates in those links. Does that mean that the project that I am using for my equipment cannot import the links without setting up a shared coordinate system?

[limartin]

Ok, from this point on, everyone can just ignore my newb posts because I am slowly losing my mind. Each time, it seems, I post a problem that I have wrestled with for hours, some kind soul replies, I go back and try one more time, and Voila! Thank you for that simple reply and I truly had tried to link these models by shared coordinates and got some error message. However, in my extensive research of the day before, I had discovered that my base model's base point had been shifted at some point, so I shifted the whole thing back. Thank you so so much.