Have Ford Questions? Ask a Mechanic for Answers ASAP
Hi there. Your Expedition is experiencing a condition we mechanics call "dead at key", which means nothing happens when you turn the ignition to START. There are several items that could cause that condition; from the anti-theft (PATS) system, to any number of possible open circuits. Best tools to diagnose this type of issue are a scan tool capable of reading engine data and a scope or good digital multimeter.
I noticed from the original post that you're hoping to fix this issue yourself; now that you know what is involved and what tools will be needed, are you ready to start?