Alternator and battery tested good, but Ford Escape won't crank?

I have a 2004 Ford Escape that has had the battery warning light on the dash for about a month. I took it to auto zone and the battery and alternator tested good. Today I'm out and it won't turn over and has no power. The battery terminals are clean and the connections look good. Any idea what might be going on here?

Ignoring the battery light for a second, do other electrical components such as headlights etc work when switched on? If they do and they illuminate sufficiently and not weak, then your starter motor may be defective. Further tests are required.

If your lights are bright…
Starter, solenoid or neutral safety switch. Put it in N and try starting it. If not the solenoid or starter is out.

Try leaving the lights on and turning it over. If they don't dim it could be the ignition switch too.

If EVERYTHING is dead, and the battery is testing good, you have a bad battery cable or a bad connection at one end of the battery cable.

Key ON, engine OFF, are there lights on the dash? No, check for power at the fuses. Power is good, check for a bad ignition switch. If you do not have a clue on how to do this, you see a mechanic. And when your car has a battery warning light that stays ON when the engine is running, you SEE a mechanic.

Bad starter.

Check the main power distribution fuse box under the hood… On drivers side just inside the fender, There's a 120 amp fuse that provides main power to the interior fuse box, other fuses and ignition /starting circuits. Check that fuse to see if it's bad /blown or any other associated fuses for the starter, ignition, etc. Replace if needed.

Owners manual… Page 157-159… For fuse locations…

When the red battery charge warning light is on the alternator is not charging the battery.
You need a minimum of 13.7 volts at the battery terminals with the motor at 1200 rpm.
Make sure the fusible links are all good. They are the larger fuses in the engine compartment fuse box.

The alternator doesn't crank, the starter does!

The primary starting circuit includes:

Starter
Starter solenoid
Battery cables
Battery terminals
Battery

If these are intact and operational, momentarily connecting +12 volts to the solenoid coil terminal will energize the solenoid, which will actuate the solenoid, which will operate the starter and turn the crankshaft.

Please do this with an automatic transmission in Park or Neutral, or a manual transmission in Neutral, so the car won't move while the crankshaft turns.

If the ignition switch is off, the engine will not run, but a manual transmission vehicle will immediately move if the transmission is in some gear.

If you can make the starter operate by doing this, it eliminates everything in the primary starting circuit. If the starter will not operate, then check with a voltmeter or 12 volt test light until you locate the problem.

If the starter operates, then you need to look in the secondary starting system

Do the lights go out when you try to start it? (headlights) if they do its probably dirty battery connections at the battery posts, It could also be the connection at the starter where the cable connects. The headlight test is a pretty easy one, and it will rule battery issues out right away