I have been messing around with my new 528e - trying to fix some of the problems before I put it into service as my commuter. I have had problems with the temperature gage and the tachometer. Neither work, and while I can live without the tach for now, I dare not drive the car without the temp gage. I have grounded the plug and noted that the needle DOES NOT peg out. Any suggestions? Is there a test I can do with my Ohm meter on the gage itself?