2006 Freightliner FLD120SD Engine: 12.5L -6; Position: Fan, Alternator and Air Conditioning;. 2007 Freightliner FLD120SD Engine: 11.1L -6; Position: Fan, Alternator and Air Conditioning;. 2007 Freightliner FLD120SD Engine: 12.5L -6; Position: Fan, Alternator and Air Conditioning;.