Engine Shut Down

My Windstar will be running fine, and all of the sudden , without any warning, the engine will shut down. No knocking, no engine warning light, nothing. It will start right up after a few turns from the starter. I am getting a squeeking or chirping sound from the belt (or maybe its the alternator). Any ideas?
Thanks.

Does it do it at idle only...or any engine speed and situation?
Year model, mileage?

Does it do it at idle only...or any engine speed and situation?
Year model, mileage?

12Ounce: It happens at idle. Happened to my wife twice yesterday, and when I checked it out last night in the garage, it happened again, all at idle.
2000, around 70,000 klm.

Thanks

If it also is sometimes hard to start up, I'm guessing the fuel pump relay. See your glove box manual for location inside the battery fuse box. Replace only with a new one if you possibly can...in other words, avoid swapping relays about.

My other guess would be the IAC valve. It's mounted atop the intake throttle body. Easy to get to. Check the connector. Some folks have had, at least short term, luck cleaning the inside of this valve with carb cleaner and WD40.

My other-other guess would be faulty cable connections to the battery or ground cable to engine block ...or just a faulty battery. This is the loooong shot guess,.... at very slow rpm your system is dependent on battery for electrical support....at higher rpm the alternator can "carry" the system and a failing battery or bad connections.

Thanks for the input.
You know that makes alot of sense, because my wife bottomed out the car in a hole. I checked voltage from the battery before start at while the engine was running, and it read right around 12/13.5
I will go over the other items on your message. I appreciate the help, I'll let you know.