[docrodg]

Need a wiring diagram to really figure out the potential issues, but from the description you gave one place to start looking is both the ground and the fuse. Possible corrosion or poor connection at the fuse block (check fuse terminals and the wire connections to the terminals) or on the ground could cause odd gauge behavior. I would highly doubt a sensor issue as it affects multiple gauges that receive info from different sensors. Also check the connection back to the sensors, a little water or corrosion can wreck havoc, and a shared connector could also be the culprit.