I'm having an issue with my A/C recently. I just noticed it when it started getting cold here in Minnesota. My A/C will only engage when set to 60 degrees, when I bump it up to 61, it blows hot air. I saw the other threads about making sure the sensor and tube are plugged in under the steering wheel, which mine are. I noticed my coolant level in my reservoir is low, could that be the problem? Faulty cabin sensor? Bad fuse? Any ideas would be greatly appreciated.
Thanks

 

Does the actual compressor disengage? Can you check under the hood with the A/C running at 60 to see the compressor is engaged and then bump it to 61 and see if it stays engaged or shuts off? Is the A/C light still lit on the HVAC controls?

It could be an interior temp sensor issue, or a blend door sensor issue.

 

Thanks for the reply. When I'm sitting in the car, I can hear it change over when I bump it to 61.

 

Possible interior temp sensor issue.

http://www.nicoclub.com/FSM/G35/Seda..._Sedan/atc.pdf

FSM for an '06. You didn't state year but others are available if you search through this folder

http://www.nicoclub.com/FSM/G35/Sedan/

The FSM has some good diagnostic procedures and some of the stuff you can do yourself to troubleshoot

 

What's the ambient temperature? I know the AC operation is related to the ambient temp. If the ambient temp is low, the compressor will not engage. The lowest setting, 60, is forcing the compressor to work, but when you set it 61, the compressor disengages.

Since fall is upon us now especially in your area. I would wait till next year to see whether the AC is working right. This way we can rule out the ambient temp. My 0.02.

 

correct me if i am wrong but doesn't the compressor need to engage to dehumidify the cabin? like when you defrost your front windshield.. i might be wayyyyy wrong though..

how low is your coolant? I know when the Infiniti dealer didn't bleed my coolant correctly, heater wasn't working properly..

 

You are correct.


There is a low temp cutoff for the ac compressor, but it's pretty low. 15 degrees or something like that. I've regularly run my ac on 30-40 degree days to Defog the windows during a snowstorm.

The FSM lists the cutoff temp.

 

what's the reason for the cutoff? is it to save the compressor from damage?

i know i can run the a/c compressor at 80+ degrees in the winter to defog..

 

Mainly to prevent the evaporator from freezing up. Possible other reasons as well.

I do not know what the temp it cuts off is however.

 

The part you need is called a intake sensor which is located in the in cabin/evaporator area. The part number is 27723-AG000 When the a/c cools only at 60 then this is the issue. Very common on I30 and QX4 models but have seen a few on the G35

 

Thanks. I've been having the same problem

 

How hard is this to swap out?

 

You will have to remove some screws from a/c box underneath dash and wedge it open where box is put together. If you have some extra long needle nose pliers it is fairly easy because the sensor just pushes into evaporator fins

 

I had the same problem. It was the interior temp sensor

 

Are the intake sensor and interior temp sensor different parts? If so, any way to decipher which one I will need?