Cadillac Repair: 95 Cadillac A/C, compressor clutch, test procedures

Question
95 Cad. DeVille 4.9: A/C inoperative.  Compressor clutch won't engage.  

Jumping A/C clutch relay engages clutch and compressor; good cooling.  Compressor relay good [substituted].

Compresor Relay coil:  Have 12v to one side, but no ground to the other, so relay will not close. Wire [dk green/white] is continuous back to PCM, but PCM is not calling for cooling [not grounding the pin].

1))What sensors will prevent the PCM from calling for cool?    2) Location and how to check them?
3) Other cause?

Thanks.  
Charlie

Answer
IS or HAS the CHECK ENGINE light ever illuminated on the dash ?.

You will need Electrical schematics, Test procedures and picture locations of the components within the system that is causing you problems of which can't be done on this website which only allows one picture.  I do not have a website so you will have to e-mail: onlineautohelp@msn.com in order to obtain the information.