Cadillac: A/C Clutch and interior temp, compressor clutch, develle

Question
QUESTION: I have two questions.  The first being, When I am in the car and set the heat or a/c or defrost, nothing happens.  The controls are illuminated (on) and someone told me it was a sensor.  Where is it located?

Question two:  A/C......How can I tell if the compressor clutch needs to be replaced versus the whole compressor?  When I start the car, I see the pulley spin a little and no more.  Not sure but not even a whole spin or two at the most.

1991 Cadillac Develle
ANSWER: On the AC compressor. If the ac compressor is turned OFF and the pulley does not spin all the time when the engine is running then the pulley and bearing need to be replaced.

If the compressor is engaged (ON) and this scenario is happening than it could be the compressor itself which will usually make a loud grinding or knocking noise.

On the AC. Expalin NOTHING happens. Does the blower work ?. Can you hear things opening and closing under the dash as you push heat, AC, defrost, etc ?.

There are alot of sensors. Are you referring to the OUTSIDE TEMP SENSOR ?.


---------- FOLLOW-UP ----------

QUESTION: How best to explain it.  If I push the button to heat and set it at any given interior temps, nothing comes out.I hear absolutely nothing.  Same for defrost, air condition and so on and so forth (all settings).  I can not hear 'doors' opening or closing.
ANSWER: Does the blower motor run ?. can you hear and or feel it running ?.

---------- FOLLOW-UP ----------

QUESTION: sorry that I am making you answer all these follow up questions, but I do thank you for your patience.  I can NEITHER feel nor hear anything start, engage or move.  There is no air movement either.  I know that the display (digital) works, but pushing a function like heat defrost or airconditioning is like pushing a button that makes nothing happen.

Answer
OK, Sounds like the blower motor is not operating and in most cases the faylt is the blower motor itself that has failed, BUT NOT ALWAYS. I can provide picture component locations and diagnostic test procedures for testing the fan syatem by e-mailing me at: onlineautohelp@msn.com and please include your vehicle yaer, model and engine size, your question and my answer when you contact me.