iCloud Not Working
With ICloud, you can remotely search, display, lock, and clean your iPhone, iPad, iPod touch, or Mac. If you're having trouble, try these tips:
Make sure the device date is correct: Settings> General> Date and time.
Make sure your iCloud account is set up on your device.
If you have multiple iCloud accounts, Find My iPhone can only be activated one at a time.
Find My Mac can only find your Mac if it is connected to the Internet through a known Wi-Fi Internet connection. If you are connected to the Internet using an Ethernet cable, this feature will not work.
Your device should be on, not off.