AC clutch engages when I run defrost heater...normal?

[Eddo Rogue]

When I slide the climate knob to defrost, and the temp knob to fully hot, the ac clutch engages. Is this normal? its a 4.0 OHV r143a coverted

 

[franklin2]

Yes. When it's cold and rainy outside, it dehumidifies the air hitting the windshield and makes it clear up faster.

 

[Eddo Rogue]

Yes. When it's cold and rainy outside, it dehumidifies the air hitting the windshield and makes it clear up faster.

Thanks for the prompt response. This was while it was hot outside, but I figure you mean it comes on regardless, as part of the defrost setting (to dehumidify)...

 

[Uncle Gump]

Anytime you go to defrost... they turn the A/C on to dry the air. Regardless of ambient temperature.

It's working as it should.

 

[Eddo Rogue]

Thanks guys, perhaps I'm being paranoid after recent wrenching trauma lol, not used to things working as they should.

 

[19Walt93]

It will run the compressor in the mix position as well. Years ago people in areas like NH would turn the a/c on in the spring and find the compressor seized because it hadn't turned in six months. Now the compressor is "exercised" during the winter and the defroster is more effective.

 

[Eddo Rogue]

It will run the compressor in the mix position as well. Years ago people in areas like NH would turn the a/c on in the spring and find the compressor seized because it hadn't turned in six months. Now the compressor is "exercised" during the winter and the defroster is more effective.

Ah that makes sense, although I would rather not have the compressor running unless I am using ac, I fund a heater setting that wont run it...did they save any engine to move truck? sheesh...

 

[19Walt93]

So put a switch in the circuit between the heater controls and the compressor clutch power wire, or select Floor, Panel, or Off.

 

[Eddo Rogue]

So put a switch in the circuit between the heater controls and the compressor clutch power wire, or select Floor, Panel, or Off.

Copy that, I'll go with Panel lol