I remember coming across a thread somewhere about how to fix the 89-92ish clusters, something about a ground solder joint I think while I was searching for info on something else. Cant find it now and think it may help as I seem to have all the signs of a bad cluster.
Speedo reads too high, seat belt, low fuel, check gauges light all on, and tach not working.
The tach may be unrelated as I also have an ses light with a code 42 for ICM which appears to also come up for crank pos sensor. May be the cause of the tach.
Anyway hopefully someone has an idea of where to find it or how to fix it if possible. These clusters seem to be getting tough to find around here.