Automator Service to insert text only available when text is selected
I found the answer here:

https://superuser.com/questions/589184/finder-not-enabling-use-of-services-when-changing-service-receives-selected-in


  OS X sometimes ignores changes to services after they've been saved in Automator, possibly due to caching. So if the service started out as a text service, chances are your changes aren't getting picked up. To circumvent this problem, select File » Duplicate in Automator and save the service under a new name, and try again. Then delete the original service from ~/Library/Services.


(Answer is by Daniel Beck)

I duplicated my Service script (in Automator) as suggested above and now it shows up in the Services menu without needing to select text.  I suspect when I first created the script that I had "Service receives text input" selected, and then I changed it later.  Note that also checking "Output replaces selected text" should not be changed after first saving the Service.