Carter Conlon's ministry preparation...

I have heard Ravenhill mention in a sermon a reference to Carter Conlon and his ministry preparation. He seemed to allude to some period of time that Carter had shut himself in with God and sought His face for a number of years in preparation for ministry. Can anyone verify this or have any information about it? Are there any sermons that maybe mention anything about this time? Any info would be wonderfully helpful.chad sepulveda