Many Moto G user have problem with LED notification. The notification light fail to turn on when they have incoming texts, emails or phone calls. The Motorola Moto G LED notification problem may be caused by restoring settings from a Google account, which could include an instruction from an older phone where the LED was disabled, or nonexistent.
How to Fix Moto G LED Notification Problems
Please follow this guide to fix the issues
Problem: LED Notification Not Working on Moto G
Solution: However, to make the LED work you can use the Notification Light Widget Android app announced by Motorola. Stick the widget on your Moto G home screen, then activate the LED again. When the LED notification performs normally, you can delete the widget.
That is some solution to fix not working LED notification on Moto G, hope it can help you.