DWG does not import

I need to import cad file into my sketchup model to update it as per the cad file I am however having trouble importing cad file into my sketchup model. When I import it, it doesn’t show up in the model. Any tips on what I can do please?

Try Shift+Z (shortcut for Camera > Zoom Extents)

There is a big blue box but nothing in it

It means you have selected a group (your dwg). Maybe your dwg file contains, in addition to the information you wanted, other entities far from Origin.
Open Outliner and see what it contains.

https://learn.sketchup.com/track/3-ways-boost-your-cad-3d-workflow

Have you looked at the DWG file using a viewer to make sure you can see something in the original file?

Is it possible that there are entities but you have a setting that renders them invisible?

What viewer do you mean? It is a simple line drawing I have stripped it off all hatches and other featrues

Autodesk have a viewer (for example) that allows you to see what the drawing looks like in Autocad. But it sounds as if you have already seen the drawing in Autocad or a clone.

You could try uploading the SU file here to see if others can reproduce your issue.

And the DWG.