1997 Cadillac Deville air conditioner

i have a1997cadillac deville. i have 2 problems service engine soon light and ac compressor off and very low refrigerant. i had the ac unit tested and freon level is good,they put dye in it no leaks. ac clutch also will not engage. i have been told 10 different things,a sensor,refrigerant level switch,a vaacum leak. one guy tried to jump the clutch with awire that didnt work. how can i get some real answers without breaking the bank.cadillac just wants way to much money to work on it.tahnks scott im in dallas