How to open a large Illustrator file (eg. 120 in x 48 in) saved in Illustrator. Then, how to open the same file to actual size in Photoshop?
You can simply go to Photoshop > open > yourfile.ai
It will bring up a window so you see the image size and artboard size. Click ok, and there you have it!
Use this image as a guide.
You might try saving file in EPS format, it must be working.