If you can describe your problem in a bit more detail, there's plenty of people on this board, including myself that'd be willing to try and help you out.
If your temp gauge has gone South, then either the connection to the sensor came loose, or the sensor itself is bad. This is not a very expensive part. Around $20 here at Fastlane.
~Paul
_____________________
'91 300E, 214K miles
|