The battery is draining.

@garonmjohnson sounds like a bad battery. Since you said you've charged it it is possible that you have a shorted cell(s) in your battery. Get an inexpensive battery resistance tester and see if your battery can provide the proper amperage or if it breaks down under load. Let us know if your Your Ford starts with a boost or if you are having trouble starting it with that as well.

I have a 2004 F250 Super Duty 6.0 liter truck and have the same problem. Ive had it in an automotive electric shop twicd. They hav rd removed components both times and yet, the problem continued. I had Interstate batteries in it, even replaced them twice. Problem still existed. I went to Walmart and bought their cheap (sorta) batteries... it's good to go. Before, even when new, the battery charge would only last a couple days at best. Now with the new batteries, its sat for two weeks and starts right up. But, still dont know if removing any of the components was a good choice.