And, O'Hare's radar is (in fact) down for maint
http://www.wunderground.com/radar/radblast.asp?ID=ORD&type=N0RYou can switch to a near-by radar (which is what is showing on Wunderground for Chicago nexrad)
http://www.wunderground.com/radar/radblast.asp?ID=LOT&type=N0RChange your Settings.php from
// Radar settings
$SITE['noaaradar'] = 'ord'; // LAST 3 characters of NOAA Radar Site ID
to
// Radar settings
$SITE['noaaradar'] = 'LOT'; // LAST 3 characters of NOAA Radar Site ID
and change WU-radar-inc.php from
$RDR = 'ord'; // last 3 characters of NOAA Radar Site Name
to
$RDR = 'LOT'; // last 3 characters of NOAA Radar Site Name
You may need to use WU-radar-testpage.php?show=loc configuration process again given a different radar is selected.
Note: in either case, the 3-character radar ID should be in UPPERCASE

Best regards,
Ken