AC inside air goes in and out

[AZ Tahoe]

Hey guys,

Noticed sometimes the button for inside air when using AC doesnt work. Light will just go off and wont come back on. Sometimes when I turn the car back on it will be working again. Any ideas?? 99 2dr 5.7 220k - 30k on new motor

Thanks

 

[SunlitComet]

sounds like the module is flaking out but exactly button you talking about? you mean recirculation button. airflow mode control? what does the voltage gauge on dash show when it is doing this?

 

[AZ Tahoe]

recirculation button and voltage has no change

 

[SunlitComet]

so if the recirc button is pressed in and light twitches and the recirc door motor with it then the issue is a funky switch. you can try getting some electric contact cleaner in the switch to see if that helps. if not replacement of thew module is required. the light and motor simply respond to the switch or temp mode they do not give feedback. in fact turn the temp knob all the way to coldest setting that operates recirc door and shuts off the water valve too. it will not activate the light tho. maybe you can handle that temp setting being in az right now.