I mean real dark can't even see it in the daytime. If I shine flashlight while driving I can see \the gauges are inoperative too. I checked all the fuses under both footwells, no help.
Any ideas?

 

Looks like the cathodes are burning out. Do a search on "CCFL" or "cold cathodes". Its easier to just replace the whole cluster. Some have replaced the cathodes with LED's (which create some hot spots) IIRC, you cant buy replacements for the stock lighting.

When you have the dimmer switch all the way up, are the rest of the lights in the car bright while the cluster is dim, or is the rest of the lights dim as well? Could be a bad dimmer switch if everything else is dim.

 

Hi, Tanin Auto here! What year is your GS?

 

Hey mine did this a couple weeks ago. Check your battery cables for corrosion. Try cleaning them. Worked for me.