You must have had bad CDs. No red LED lit = no OS software loaded in nav comp.

If you have the 4:3 display and a Mk3 then split screen only works with the Professional RDS tuner. It does not work with the Business RDS tuner.
Check what tuner you have - cycle throught the FM modes, if you see a mode labelled "FMD" then you have a Professional RDS tuner.

I have heard but have not confirmed myself that radio-split screen with the 16:9 widescreen mode may not work.

Also, use my NavCoder app and make sure the nav is properly coded for splitscreen mode (that's the Radio type setting)..