If you import using media browser you will not see source TC. Try right click in the bin and choose import from there. I don't have a clue why it works this way.
Use the "Information"window. It shows you the current TC of the sequence and the matching TC of the source clips for all your video and audio layers.
By the way, an overlay right in the program monitor (like FCP7) would be more practicable.
Sorry I might have confused the issue, I already edited the source video into a sequence I now need to insert graphics based on the source TC not the sequence TC.
If I put the source back into the source monitor I do see the source TC
I agree. We need source TC overlays for Source and Record Monitors. Please make a feature request: http://www.adobe.com/go/wish
In the mean time, you can use the Timecode window. Choose Window > Timecode and select the video track you want in the Panel menu. That will show you Source TC in the sequence.