Possible Problem: Air conditioner compressor clutch stuck engaged?
I spent the morning doing some maintenance on an 2003 C320 (60k miles now) and noticed an unusual noise coming from the engine compartment. Upon further inspection, I noticed that the sound was coming from the air-conditioner compressor. I went in the car and turned off the A/C by hitting the AC Off button (digital A/C). Looked back at the compressor and noticed that the clutch was still engaged and the belt was still running the compressor. Then tried cycling on and off by pressing Auto and decreasing the Airflow volume to 0, or pressing the AC Off button on and off. Clutch was still engaged no matter what.
Anyone else have noticed this problem? Could the clutch be mechanically stuck? Could the A/C controller be bad?
I recall, about a year ago, that this happened before (stuck clutch) and never thought of it being a problem. Also, the car was brought to the dealer right before expiration of the basic (50K warranty) since the A/C stopped working. They said they only refilled with r134 to fix it.