Cadillac Repair: 2000 Cadillac STS, volt ohm meter, twilight sentinel

Question
The Twilight Sentinel Sensor continually reads Dark even in the brightest sunshine.  When the Twilight switch is in the off position a message displays reading "Headlamps Recommended".  When the Twilight switch is in the on position the Headlights go on automatically even in the daylight.  It's my understanding that this sensor is located under the Defroster Grid which is next to impossible to remove.  Any ideas what is causing this problem and how I can get at this sensor to eithr clean it or replace it?  Any suggestions would be appreciated.

Answer
What you need to do is make sure that nothing is covering the sensor FIRST.

Second, You will need several pictures and test procedures which will require the use of a $20.00 DIGITAL VOLT/OHM METER which you can purchase at any auto parts store or even WAL-MART sells them.

Then you need to e-mail: onlineautohelp@msn.com