Air ice cold with A/C off

[Prophet7000]

So I've been having this weird problem with the A/C in my '98 Mounty for the last couple of months.

When the A/C or max A/C positions are selected all is well - ice cold air. I can hear the A/C compressor kicking on but nothing else out of the ordinary.

Now when I select the upper vent only, floor only, or dual, the air is still ice cold. And this isn't just shortly after turning off the A/C. I can ride in the car for literally 5 hours with the A/C off and it's still ice cold. I know it's not a blend door issue because the air will get warm if I turn the blend knob to warm.

I'm guessing the compressor is still cycling (since I can hear it) with the A/C off, but I have no idea why or how to fix it.

Thoughts?

 

[hworksinc]

The AC compressor is designed to cycle in ALL positions (except vent only I believe). It's normal behavior, and permits better control of in-car temperature. You should notice that this automatic cycling is less frequent in the winter and more frequent in the summer.

 

[Prophet7000]

The AC compressor is designed to cycle in ALL positions (except vent only I believe). It's normal behavior, and permits better control of in-car temperature. You should notice that this automatic cycling is less frequent in the winter and more frequent in the summer.

Be that as it may, it does not explain why the air is ice cold when the A/C is off.

 

[heathmo]

I think it only doesn't cycle in floor, I'm pretty sure I've had mine cycle on vent, even though it blows warm air.

*Edit: I honestly don't know why it would still blow cold, I'd be stoked if mine did, the vent on mine sucks, just straight warm, usually with a mix of engine heat. Because it can be pretty cool at night and it'll still blow warmer air than outside.

 

[Prophet7000]

I honestly don't know why it would still blow cold, I'd be stoked if mine did, the vent on mine sucks, just straight warm, usually with a mix of engine heat.

Yeah and we're not talking just colder than outside, I'm frankly surprised icicles aren't firing out the vents when it's 100 outside. Overall it's not really a huge problem since I can still get hot and cold air, but I worry this issue is a prelude to something expensive breaking. It's not everyday your A/C actually gets colder (and stays on).

 

[Diff Whack Daddy]

Turn your temperature knob up. This is actually common. I drove my 2000 F-350 all the way out to Moab and back and never actually turned the AC "on". The fact that the compressore always cycles, creates the cold radiator for the air to flow through, means that there is always cold air available. My 97 expedition did the same thing as well as my sons 95 Explorer. It's like a sink, mix the hot and coll air to get a comfortable temperature.

 

[Prophet7000]

My 97 expedition did the same thing as well as my sons 95 Explorer. It's like a sink, mix the hot and coll air to get a comfortable temperature.

Weird. I just won't worry about it then. What creeps me out is that this frigid cool air, with the A/C off stuff just started happening recently. Maybe it just coincides with the warmer weather around here and the compressor is just cycling more due to the exterior temps.

 

[Diff Whack Daddy]

Weird. I just won't worry about it then. What creeps me out is that this frigid cool air, with the A/C off stuff just started happening recently. Maybe it just coincides with the warmer weather around here and the compressor is just cycling more due to the exterior temps.

Most likely you don't notice it much in the cooler temps because you temperature knob is already set to a warmer temperature and or the ambient air being warmer, there is a more noticeable difference.

 

[budwich]

your ac shouldn't "cycle" at all in the "vent only" or "floor only" positions. You have switch control issue and not a blender door issue.

 

[TheJackal]

If the knob is in the "Off" position how do you know it's ice cold?

Try observing the compressor clutch with the switch in the "Off" and "Vent" modes, versus the other modes. If the clutch engages any time in "Off" or "Vent," you might have an electrical issue.

 

[Prophet7000]

If the knob is in the "Off" position how do you know it's ice cold?

With the A/C off, meaning it's on vent, floor, or both - not on the A/C or max A/C settings.

 

[Prophet7000]

your ac shouldn't "cycle" at all in the "vent only" or "floor only" positions. You have switch control issue and not a blender door issue.

I'll take a look tonight and see what settings the A/C actually cycles in.

 

[hworksinc]

your ac shouldn't "cycle" at all in the "vent only" or "floor only" positions. You have switch control issue and not a blender door issue.

Quite right. The AC compressor will be ON (That is the AC will be on) in A/C, Mac, A/C, Vent/Floor, Defrost/Floor, and Defrost. See below:

The A/C is never truly "OFF" unless the switch is in OFF, Panel only, or Floor only. The A/C and Max A/C positions are just "Vent only" with the A/C on.