Ac clutch cycling with heater on

[john cris]

When the heater is running the AC clutch cycles which I think is normal. But I noticed that the idle rpm also drops when the clutch engages. It’s more of a bounce, as it trips on the rpm will drop momentarily. The clutch cycles every few seconds. I haven’t seen that occur before. Something doesn’t seem right. Suggestions?

 

[kydirtscooter]

Low refrigerant charge

 

[john cris]

why does the AC clutch cycle when using the heater? Are vehicles with no AC that much different? I haven’t used the AC in a long time. The system functions and was recharged a couple years ago. Maybe I can just eliminate the AC?

 

[donalds]

It cycling is to remove moisture from inside the truck

The cycling is normal
But if it's happening every 10-20 sec then most likely low on Freon

 

[john cris]

Noticed this morning that it cycles the clutch only when the defrost is on. The rpm drop wasn’t as much as yesterday. I’ll check the Freon charge.

 

[kydirtscooter]

I wouldn't delete ac. It makes a measurable difference in defrost/demisting windows.

 

[mountaineer2004]

It's normal for the AC to engage in both defrost and floor/defrost, at least with temp above mid 40's or so.

 

[john cris]

Just checked system pressure:
Low cycles 20-40
High 50-75

 

[john cris]

Checked system
Low cycles between 20-40
High cycles between 50-75
Ambient 45-50 degrees

 

[TechGuru]

That's very low. But my ambient temp was probably 80 degrees when I checked it back on August 9th.



I can't even find a chart that goes down to 50 deg ambient.

 

[john cris]

I couldn’t find a chart that went that low either. I’m going to run a can of dye through see if I can find a leak