It loads as an absolute everytime so terrain must be turned off to see the lines. Any idea how to get it so they default to clamped to ground? Using newest version of GE.
The Google Earth help discusses the different options for toggling this setting within Google Earth, however none have the permanence that you need.
If you just have a small number of KML files to alter you could simply edit them in a text editor using search and replace to replace the line
If you have many files to do, or will perform the operation many times you may find it better to modify your KML files using python to perform the find and replace across may files automatically. I recently wrote a simple regular expression to perform a similar task which I have modified for this problem:
This will replace any altitude settings with your desired settings, and could be nested within a loop to iterate though a folder full of KML files, if needed.