Jasonaford

My 2011 Suburban will not put out conditioned air when the outside air temperature is at or below freezing. The a/c light blinks 3x and turns off. I have replaced the ambient temperature sensor and the pressure sensor, with no success.

I want the a/c to come on because I need the dry air for defrosting, not for temperature control. I don't have a temperature problem, I have a humidity problem.

Is there another sensor to replace? Is there a way to bypass, jump or workaround the system turning itself off?

Since it can still be humid inside the cab and fog up the windows even when it's freezing outside, this seems like a faulty system or sensor error.

Thanks folks.

kevinkpk

Maybe it's trying to tell you something?

Rednucleus

The a/c should engauge run when put in defrost setting. You should not need to turn on the a/c seperately for this

tech2

+1.
on defrost the ac will run intermittently to help with fogging glass but it will not run for long. the system can'T get to cold or the evaporator will freeze. best way to deal with fogging is to keep the inside glass clean.
does your year run a orfice tube or thermal expansion valve?

73shark

Welcome to the forum. The A/C will not run below 38°F. I'm wondering why when it's that cold out that you have a humidity problem. Have you checked under the carpet to see if any of the fiber backing is damp because you may have a leak someplace. That will cause a high humidity inside the cabin.

Moving to the Suburban section as this is the welcome new members section. You will get more views there..

Jasonaford

[QUOTE=73shark;475951]Welcome to the forum. The A/C will not run below 38°F. I'm wondering why when it's that cold out that you have a humidity problem. Have you checked under the carpet to see if any of the fiber backing is damp because you may have a leak someplace. That will cause a high humidity inside the cabin.

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The humidity problem is simply from a large family's hot breath. Just because it's cold outside doesn't mean that the breath inside is any less hot or humid.

Without conditioned air to dry out the air inside the cabin, windows fog up.

I have had several cars from many decades and none of them shut off the A/C because of the outside air temperature.

This seems like an error in the computer logic.

Does anyone have a workaround to bypass this logic? Has anyone bypassed or jumped the sensor that's causing the system to kick off?

Thanks.

repairman54

A/C running below 38F will damage the system. Purposely designed and no override so system is protected.
Make sure you are not using Recirc. as we want outside air coming in to vent out moisture.

Rednucleus

Will the a/c start working as the under hood temps rise when the engine warms up?

repairman54

No, it goes by what the outside air temp. gauge is reporting.