Might be time to pull the cluster. Could be the lamp is burned out, or possibly the PO removed the bulb so as not to be bothered by seeing the light come on everytime he spun the tires.
'73 280SEL 4.5 (9/72)- RIP
Only 8,173 units built from 5/71 thru 11/72
'02 CLK320 Cabriolet - wifey's mid-life crisis
2012 VW Jetta Sportwagon TDI...at least its a diesel
Non illegitemae carborundum.