First post here so apologies if I do something wrong

Anyway, I am the owner of a 2000 S10 Blazer and have been having issues with the gauges ever since I brought it out of winter hibernation (it was sitting all winter)

The RPM gauge and the fuel gauge are having some issues

The RPM gauge is stuck on max and won't go down. engine runs fine so it's just stuck.
The Gas gauge alternates between completely empty with the gas light on and full and I have no clue how much fuel I have in the tank.

Not sure whether this is an electrical issue with the instrument cluster since I got this one from a scrapyard.

Any help is appreciated

 

I would pull the cluster back out. Disassemble it, see what is going on with the tachometer. Maybe something simple, maybe trash.
The fuel gauge could also be a bad contact in the cluster. To rule it out, you would need to put a voltmeter on the fuel gauge signal line, see if there is a voltage there. Could also be a cut in the wiring at the fuel pump connector.
Check the connector on the cluster, and the connector pins/contacts in the wiring harness...could be as simple as dirty contacts or a contact pushed out....just need to look it over good....once the cluster is out.
Good luck and let us know what you find.