Oil guage quite working

Hi, this is a pretty common problem on these Silverado instrument clusters. We can repair it for you or provide you with the parts to do it yourself. Click here to learn more about these silverado instrument cluster problems:
Dr Speedometer Instrument Cluster Repair Speedometer Repair Guage...

Check the oil switch wire/terminal, may be it disconnected or dirt,
the last thing to do replace the Oil Switch.

First thing to check is the oil sending unit. Check to see if the wire is attached snugly.
Changing the oil sending unit is easy and fairly inexpensive. This should solve your problem.

I beleive your oil sending unit is on the very back top right corner of the intake manifold, but screwed into the engine block.

Check the fuses and check to ensure the wires are connected properly to start with sometimes the oil pressure switch can go bad they used to be fairly priced call around to get an idea but start with what i suggested 1 st