cranking problem in 97 escort

97 escort lx wagon 120,300 miles. There have been a few times in the past 2 weeks when I go to crank it up, everything lights up on dash, there is a humming noise like everythings suppose to do(fuel pump sound) but it doesn't crank. If I try a few more times, or wait a few minutes, then it will crank right up. and it has happened even after I have been out driving for awhile, not from a cold start, it's just random. I replaced the alternator in '01. I just replaced the battery back in june/july, any ideas? could it be the starter?

I forgot to add that when it does crank, it makes the sound like all the doors are locking like if you have auto door locks. I have the remote door locks that work with the remote on a keychain(which I don't have anymore) but that's the only way they are auto locks

Up until you mentioned the sound of the doors locking I would have agreed it sounded like a starter that was on-its-way-out. My 92 Escort was doing the same thing. Sometimes it would crank on the first try, sometimes it took several tries. I suspected the neutral-safety-switch, but didnt replace that because it is so expensive. I suspected the ignition switch, and put in a new one. The electrical part of the switch, not the keylock part. That also gave me the chance to cut the white wire that causes the key-in chime to work. (I really didnt like that chime!)
I ran a wire of my own from the solenoid atop the starter, over to where it would reach the postive terminal on the battery. Touching that wire to the battery terminal would make the starter crank 100% of the time, even if use of the ignition switch did not. Finally I replaced the starter and the problem ceased. The car had 192,000 at the time.

When it fails to crank, does anything else fail too? Do lights still work? Radio, etc?
Perhaps a bad ground somewhere... possibly the ignition switch.

You put in a new battery so are the terminals clean and tight? That sound like the doors are locking is thle solenoid kicking in and out.

terminals and all are fine. everything else lights up and works. I'm thinking it's the neutral safety switch. Monday was the last time I had a problem. The sound of the doors unlocking was exactly that, the trigger for the doors to unlock. The neutral safety switch is only $28 so I'm going to try that.

Neutral safety switch and ignition switch are easy to test... check the circuits before you start buying parts.

how do I test them?

Disconnect the neutral safety switch and use an ohm meter... with the tranny in P or N there should be continuity through the switch, if not, it is bad.
Do the same with the ignition switch... with the key turned all the way you should have continuity through the switch.

Another easy way to test the ignition is to just disconnect it and use jumpers. If the engine cranks, then you know the switch is bad.

that's only going to work if it's not cranking. if it's cranking then the test are going to show everything is fine. and just cause it doesn't crank once, deosn't mean it's not going to crank the next try so how am I suppose to test it?

Well then test it multiple times... manipulate the switches and try to get it to stop working... or wait until the next time it quits working and test it then.

I'm not the one driving it when it happens, it's always my wife, it's her car. I've replaced the neutral switch already so I'm going to see what happens the next wek or so.