4wd warning light flashes 3 times intermittently...
If anyone can tell me which error this means, I would appreciate it.

 

3 flashes indicate failure in transfer case front drive shaft speed sensor circuit, wiring, connectors or sensor. Check all the wiring harness for any damage and ohm + short test. Wiring and connectors are often damaged or corroded on these especially salted roads. Can try cleaning sensor of all debris internally. Sensor is NLA, used junke yard only.

AWD does NOT function with this failure. AWD controller under the driver seat locks out transfer case from AWD.

http://www.rsgear.com/articles/1999_06.pdf

 

Thanks for the great info!
The van belongs to my 2nd cousin and she loves her old van. The shop she used to take it to told her to junk it but she asked me to fix it up. Nothing major (yet), but it is rather difficult to work on and some parts are NLA. Luckily, I found someone locally who has a 96 Eddie Bauer edition with a blown engine. Will the AWD systems be the same or at least have some interchangeable parts?

 

At least all the 4wd sensors should be the same, so you should be able to swap them over and see if that fixes your problem.

 

The transfer case including the speed sensors are the same between 1992 and 1997. I don't remember error code I was getting but on my 92 nothing I did with the speed sensor corrected the problem, I ended up having to switch out the transfer case. In that case there was a lot of play in the driveshaft at the transfer case that in the end caused the transfer case to crack.