Water leaking in

I have water that pours into the cabin after every hard rain. The water mainly comes in on the passenger side behind the fuse box but sometimes pours into the drivers side as well. You hear the water rushing in after the van starts moving (it does not leak in when the van is in motion, only if it is sitting in the rain). After a while the electric windows will not go down, the doors have to be locked and unlocked manually and the door chimes won't work. After a day or so it will all work again.

Do you have a luggage rack? Water could leak around the bolts.

Do you have a luggage rack? Water could leak around the bolts.
I'd also check the seal around the top of your windshield. Some Ventures had a problem with poor seals. Mine had a poor seal and would drip inside the van around the middle of the windshield, (above the rear view mirror on the windshield.) I even have rust that has broken through on the passenger side roof where the windshield seal is located. It appears that is where the water enters the vehicle and travels down toward the middle of the windshield and drips out.