hi My Name is Dan,
Is the Alarm Light Flashing On Dash.
each lock cylinder on van has a switch for alarm , try unlocking both front doors and rear
lift gate and see if alarm goes off.
If you have a gray key it is a skim key . If you had a bad key the van would of started and died 3 times . a new skim key is around 36 dollars and then you need it programmed with the van. you may have a bad body computer. with out checking vans computers. its hard to tell. I wish i could help you more.