2008 Kia Sorento Q&A

2008 Kia Sorento Question: AC unit knocks and rattles when turned on

when I turn on A/C my car makes a horrible rattling and knocking. Sometimes it cranks rough as well and when it does that it runs rough for the first minutes -
Answer 1
Sounds like the AC compressor clutch is failing, how does it run with the AC off? -