A/C Compressor engaged all the time

[jwichman]

I have a new to me 2008 Impala LT with the 3.9L engine. The temperature blend door controllers chatter occasionally but ususally cease after a minute or so. The vent heat defrost mode control seems to work as it should and the fresh air recirc seems to work as it should.
Today it warmed up to 50deg and I noticed the AC compressor was engaged anytime I turned the blower switch on and the mode was in floor or any of the defrost settings. With the blower switch in the off position the compressor dosengages but re-engages as soon as the blower is turned back on (just in floor and defrost settings). The light on the AC button will light when the button is pressed and goes out when pressed again but does not seem to control the AC compressor. The compressor operates with the AC button and light correctly when in vent or bi-level mode.
Maybe when in defrost mode the compressor should engage without use of the AC button but it doesn’t seem that the compressor should be engaged when in the floor mode only. Any thoughts?
Thanks!

[jwichman]

I came across a similar thread that referenced the AC operating condition description from the Owners manual. After reviewing my owners manual it seems my system is working correctly.

[j cAT]

Originally Posted by jwichman

I came across a similar thread that referenced the AC operating condition description from the Owners manual. After reviewing my owners manual it seems my system is working correctly.

ac will turn on in def mode.. also the air will blow out the floor lower also.. if its below 40F the compressor will not stay running .. could turn on a sec or two then shut off..