Is the van overheating temp. going to HOT? Fans take a long time to come on! Sometimes 30min. Do they come on with ac turned on? If ac is working. If not working after these test THEN start looking for other stuff!
How did you check the fan module? . . . You have a fan relay that usually fails on this vehicle...it is hard to access and it is under the battery tray...buy another fan relay to get an idea what it really looks like...then match it up with the one in your van and replace it.