I am researching this problem right now...and its going to be a hunting expedition.
So before I reinstalled my center console I started my 90 and it fired right up. Yesterday I got everything buttoned up and all went fine. I did not start my truck. This morning I decided to take a run in to Austin to put some miles on because the trucks been basically sitting for three weeks.
Put the key in and got the chime. Turned on the ignition and nothing...I thought the battery might be drained, so having a dual system I flipped to the back up and nothing...still no start. So I put the auto in neutral turned the key and it started. The low battery idiot light was on. So I hit the highway with AAA card in hand. While driving I noticed the tach, temp, and speedo including the odometer are dead. The fuel gage was working but not accurately. The clock was/is running. The windshield wipers will only work on hi speed and the sprayers do work. the battery idiot light stayed on although dimly the whole round trip.
So I get to Austin and shut the 90 down do my business and the same thing all over again. The truck runs fine when she started...I made it home after a repeat of the first event. The only thing I can thing of is that while putting the center console back in I popped a fuse out or something. I'm looking for the diagram now but haven't located one for a 97SW D90 yet.
It's not likely to be the batteries...something's blown or shorted to take out those gauges...going out to check fuses now.