When mine did that, it was caused by wires pulled loose in the steering column.
My wife was driving the 2001 Sport Trac and complained that it would not start. When I got home from work, it would start right up? It did this intermittently for months. Finally, it would not start when my wife was visiting family in Louisiana. The truck was still under warranty, so she called a local Ford dealer. They towed the truck to the shop and worked on it all day before one Tech remembered a TSB that said the wiring harness in the steering column can get pulled loose and cause intermittentent problems when the Tilt wheel is moved. Sure enough he checked and found the connector in the steering column was pulled apart enough to cause loose connections. He fully plugged the connector and pulled up a bit more slack in the steering column wiring harness and I never had the problem again.
The loose connection in the steering column can cause very strange intermittent problems with any circuit that runs through the steering column...that includes ignition, starter, accessories, turn signals, headlights, taillights, horn, wipers, cruise control, etc.
...Rich