DEARBORN, Mich. (AP) — A parts shortage that has thousands of Ford’s most-profitable vehicles sitting on lots waiting to be fully assembled has forced the automaker to slash its third-quarter earnings forecast. Ford said Monday it is expecting to be missing the necessary parts for as many as 45,000 vehicles. Most of them are SUVs and popular truck models, some of Ford’s biggest money makers. The company based in Dearborn, Michigan, now expects third quarter earnings before interest and taxes to be between $1.4 billion and $1.7 billion. It reported adjusted earnings before interest and taxes of $3.7 billion in the second quarter.