Electrical system incl windows, speedometer, gauges

You need to have the van scanned with a OBD2 enhanced scanner, not just a code reader. there will be codes related to your problem. Sounds like a problem with the Body Control Module. That costs way to much to guess to buy.

Loss of dashboard gauges, often accompanied by no-crank, no-start conditions, is a known problem with these years with some of the solder joints on the gauge circuit board. Solution is to replace board or pull and resolder broken joints on the existing board.