On my wifi network there are two Mac (MacBook,MacBook Pro) and two iPhones (iPhone4, iPhone 5).
The MacBook Pro has been updated to OS X 10.10 Yosemite.
The MacBook cannot be updated to OS X 10.10 Yosemite.
Location Services work fine on the phones (but they have GPS in any case).
On iCloud.com "Find my iPhone" finds all the devices, and gets a location for the iPhones and MacBook, but not the MacBook Pro. "Find my iPhone" can send an alert sound to the MacBook Pro and that works.
Also on the MacBook Pro the location is not found for the Weather or for Maps or for Google Maps in Safari.
Seems to me Location Services are not working for the MacBook Pro.
I have tried turning "Find my Mac" on and off with no result.
Best Answer
Got around to looking at this again, with some searching on the WWW and the assistance by telephone with a 'senior' apple advisor.
What I found on the WWW was reports of com.apple.geod showing "not responding" in Activity Monitor. This process is needed for Location Services, so if it is crashed location services won't work.
Force Quitting the process in Activity Monitor seemed to enable Location Services, but on restarting the Mac com.apple.geod crashed again.
So (on the advice of Apple) I removed com.apple.GEO.plist from MacBook Pro HD▸ Users ▸ username ▸ Library ▸ Preferences (from hold down option Finder>Go>Library then select Preferences - if you don't hold down option, Library is a hidden folder). Then I restarted the Mac. This time everything seemed to work. So maybe it is just a corrupt .plist file. I get the "Location" icon in the menubar now.