Compressor with defrost

[Waynerd]

So 98 Cherokee 4.0. ac compressor always cycles when set to defrost. No matter outside temp or humidity. It will always cycle. Did some searching and it almost seems like that is normal. The 01 rarely cycles the compressor when not set to AC. So anyone know if 98's cycled all the time every time on defrost regardless of ambient air? Or is there a problem with a switch or a problem in the selector? Found some threads on adding a switch to disable compressor when it's not needed. If that's what I need to do then so be it. Can't compare it to my other 98 because that compressor never runs whether on AC or not. Lol

 

[Digger87xj]

all manufacturers run the a/c in defrost mode. It dehumidifies the air, clearing the windshield faster.

 

[Waynerd]

But I thought I read some time ago about there being a sensor or something that senses either temp or humidity to determine whether the AC is needed to dry the air also.

 

[Wayne Sihler]

But I thought I read some time ago about there being a sensor or something that senses either temp or humidity to determine whether the AC is needed to dry the air also.

No sensor.

 

[Waynerd]

Right on. Thanks guys