97 s10 blazer erratic gauges

while driving i notice fuel gauge suddenly jumps and move up and down registers 1/4 tank when half full oil pressure guage fluxuates at highway speeds above and below mid scale. voltmeter does the same oil and voltmeter are more stable fuel more erratic 82k

Do all of the dashboard lights work when you turn the key?(PRNDL, ABS etc.) If this all started to happen all of a sudden, it could be your ignition switch. See my thread on the 2001 instrument cluster. The pink wire seems to be the culprit. If you can, try wiggling the wires going into the ignition switch and see if this helps. If it does, replace the switch. You will have to partially disassemble the steering column to do this, but you shouldn't have to remove the steering wheel or the airbag (if you have one).

1.) Fuel Level will change a bit with the fuel sloshing in the tank and coming to a stop or driving up hills.

2.) Oil Pressure is directly related to engine rpms. Faster the engine speed, the higher the oil pressure.

Sounds normal to me. They don't stick at one stationary spot.

already replaced ign switch no gauges stick oil pressure fluctuates at constant speed as does fuel gauge i'm thinking common ground issue or a back feed althought i dont see any commonality between gauges need to check a schematic running 50/50 blend of synthetic and max life valvoline oil not an oil pressure issue as far as i can see

Yea, reseat you computer grounds.

comp grounds on the computer or on the body??? where are they??

You will have to look.

Reseat the computer connections just incase they are not fully in place making a good connection.