Wipers will not turn off

Hello, I assume that it is only the front wipers that will not turn off? And as for the turn signals, do the brake lights still work and will the hazard lights come on from the switch?

The module (computer) that controls the actual wiper motor gets its power from the "Totally Integrated Power Module (TIPM)". This module receives a signal to turn on the wipers from another module on a BUS network in the vehicle. Pretty much everything in the van is controlled on these networks. It's one module talking to another module on a CAN bus network.
The Turn signals are powered up by the TIPM as well, the multifunction switch on the Steering Column that controls the turn signals sends a message on the network to the instrument cluster module, that in turn sends a message to the TIPM and the turn signal lamp is turned on. So it might be that the Multifunction Switch on the Steering Column is causing both faults here. That seems more likely because it controls both options. The Steering Column module can be scanned for diagnostic trouble codes or the Live data from that module can be watched to see if any issues can be identified from there.
Sometimes all it needs is for a module to be reprogrammed or updated.
With modern vehicles and everything being on networks now it's not as simple as checking a single relay. But both issues can definitely come from the same switch,

https://www.2carpros.com/articles/can-scan-controller-area-network-easy

So, it can be the Multifunction switch (the one you use for your turn signals and wipers), or the Steering Column module, or possibly the TIPM that powers both these systems up. There's no way to tell without hands on testing and some scan tool data. The TIPMs are known to have a lot of problems, it's basically a real big smart fuse/relay panel. The Fuse for the wipers is J20 (3rd diagram) in the TIPM, it should be located in the driver side engine compartment. If you want to take the fuse out to temporarily stop the wipers until it gets looked at.

This is the Multifunctional Switch you use for Turn Signals and to turn on the wipers. If it happens that this switch is at fault, the whole unit will be changed out. But it needs to be diagnosed properly, since there are variables here, such as other component failures that can cause these issues. When it comes to all the modules involved, the TIPM, Steering Column module, Electromagnetic Instrument Cluster module. All these make it difficult to give you the answer to what is actually at fault. If it happens to be the Multifunction Switch the 3rd diagram shows what would need to be replaced. If you, have it at a shop and you're unsure of their diagnoses, you can always message us, and we will be able to explain what they have tested and what they think the issue is. Just write down everything they say and tell them you want to know what they have tested and the results of those tests. That way we can make sure they are not replacing unnecessary components. If you read through the last page here and you can see how complicated the turn signals system is.
But these switches can't just be swapped out, the SRS system (airbags) needs to be disabled and the Steering angle sensor will probably need to be recalibrated. But there should be diagnostic trouble codes stored during a full system scan that will give a technician direction in the diagnoses.