I have a 93 corvette, i just noticed recently that the instrument panel where the digital odometer is gets dim after driving for awhile and its even hard to see the digital numbers on the panel i checked the volts reading and noticed that it sometimes gets lower around 13 or even under sometimes, what could this be?

SOURCE: Dim light in instument panel at night on my 1989 corvette.

there could be a bad connection between your dimmer switch and the lights themselves. often times through vibration and wear and tear the connectors degrade. check this first. also the dimmer switch itself could be the cause.check all the connections associated with the panel lights, look for loose wires and/or bad connections if there are none replace the dimmer switch

SOURCE: Dim Headlights. 2001 Jeep

seems like a power issue, you could try buying a new battery or take it to an autozone and have your voltage checked battery should be putting out near 13 volts.

SOURCE: 1986 corvette no power to

It is your vats system it is locking you out. It is not reading the ignition key chip. You can by-pass the system with $5:00 worth of parts from your local radio shack. You must read the resistance across your key chip first then go to radio shack and pick up the resistors needed to match your key chip(they will assist you mine read 1850 i have a 86 vette), twist/tie them together then solder & tape them up with electrical tape. Bend them into a u-shape, locate the the 2 wires that run to your vats logic module that is tied into your ecm, should be in the middle area of your dash next to your radio(yellow and brown in color. Cut those 2 wires and add your (radio shack) resistor series between them and happy motoring no more vats problems for ever. Good Luck