fan now cycling and working correctly ,changed the ecm and still never cycled so removed the thermostat again to be sure it was not in backwards. i never saved the antifreeze like i did every other time and just topped up with water and the system worked correctly so i figure that the system was full of pure antifreeze instead of mixed and from what i have read it has to have a certain amount of water in the mix for the antifreeze to do its job of removing heat .i never put the old ecm back in but will to see if it works corectly but am confident it is working and the antifreeze was the problem.

 

Think you may have still had an air pocket that you finally got rid of as most antifreeze is already premixed now days(50/50,60/40,etc) plus it wouldn't have hurt it even if it wasn't. Either way glad it's working ok.