does defrost run ac compressor

We definitely have enough humidity up here in the rainforest

 

Hi all.

1 - The A/C comes on automatically when defrost or floor/defrost is selected.
2 - The A/C will not come on when manually selected if the ambient is 0 degrees C. or lower.

A question to the experts :
Does the A/C come on automatically when defrost or floor/defrost is selected and the ambient is 0 degrees C. or lower ??



- I will be doing my own testing to confirm anyway when I can get access to a heated garage (it's cold here...).
- I have started using the floor only setting since it does send some air to the defrost vents and works to defog the windows fairly effectively in all but the worst conditions.

My reason for becoming concerned about this issue is my gas mileage dropped from 19 - 21 down to 15 - 17 MPG due to the A/C coming on every day when I was selecting defrost.

Thanks guys.

Cheers
Ray.

 

Humidity comes from a lot of places. If you've been outside in the rain or snow, the water on your clothes condenses on the windows-AC rocks for getting rid of that

 

Hi all.

Here's the poop when it's cold out on my '12. My tests were done at minus 13 degrees C. The 0 degrees figure used below is from the owners manual.
- below 0 degrees C. the A/C compressor does not kick in even though the light comes on when manually pushing the button.
- below 0 degrees C. the A/C compressor does not kick in to help defog the windows when defrost or floor/defrost is selected.

The A/C compressor has a cover in front of the belt pulley that only turns when the compressor kicks in. This makes it very easy to tell when the unit kicks in.

So as with most newer vehicles the A/C system does turn on automatically (with no indicator light) to help defog the windows when defrost or floor/defrost is selected - when the ambient temp. is above 0 degrees C. When the ambient temp. is colder the A/C will not turn on when selected manually nor come on automatically when defrost or floor/defrost is selected.

Cheers
Ray.

 

mine doesnt run ac

 

I did the A/C mod. For 2009+ Tacomas you don't just cut the wire, you have to splice it into a 12v supply, otherwise your compressor doesn't turn *off*! The write-up should have details, otherwise I can pull my glove box out tomorrow and snap a picture.

In Texas, where we don't have humidity, let alone rain...or water or any sort...

 

Interesting. I am pretty sure my AC kicks on even under 0 deg c in my 06 whenever i have it on defrost/feet... which is all winter. Gonna have to look into this. Time to find my owner manual and play with the AC Wonder if the older models didnt have the temperature cutoff?

When you say ambient temp, is this just the air in general or what a scan/ultra gauge is reading for the engine bay?