F150 supercrew cab won't start,,battery good

Hey John, did it start with a jump ? what about starter relay and selonoid

check ignition switch sir

Parasitic drain on electrical system .
How to Find Parasitic Battery Drain

IF YOU JUST REMOVE THE ALARM THAT IS WERE THE PROBLEM LIES YOU HAVE THE MAIN IGNITION WIRE THE YOU MOST CONNECT FOR YOUR CAR TO START

The most common problem is the battery cables aren't making a good connection at thebattery. The only good way to check is to remove the cables scrape them off till their shiney as they connect to the battery and clean the battery posts too. connect them and tighten good and try it out.

Try jump starting the vehicle. It may have a bad battery.

Jump what? Jump start the battery? Yes you can jump it.

Yes, i would check the starter for lose connections.

dk mak r

As a retired electrical engineer this intrigues me. If you were my neighbor I would put an ammeter in series with the batteery lead to see just how much current is being drawn by the "mystery" load.

When you disconnect or hook up the battery can you see any sparks when the cable touches the battery terminal?

If the battery can get run down over night that is a significant drain.

If there is some sign of spark when you connect/disconnect the battery lead try the following.
Selectively remove a fuse in the fuse panel, (starting with the larger fuses, 15A, 20A) and then connect the battery terminal and see if you still have a spark.

Hope this helps Good luck Loringh