I have a 93 Lumina Z34 as of a couple of days ago my gauges have gone nuts but sometimes they work to. When I mean nuts I mean needles bouncing around no battery charge indicated fuel is off and speed and tach needle bounce. This is also affecting my amp and head unit protector light is on amp and the stereo just makes thumping noises. Please help . I ve checked the fuses, relays, battery cables everthing is good

 

Loose connection somewhere or a bad ground. Just start checking everything. Could be anywhere.