If you're sure the GPS is enable and there aren't any runtime errors in your code, it may be the way you're testing.

Input.location.Start() method has a default distance value to be updated. by default it has 10m, thus you need to walk 10m to see the changes. Change those values at the moment of initialitation.

Input.location.Start(10,0.1f); // accuracy, every 0.1m