# Carwash disabled my A/C



## johnclark12 (May 19, 2017)

Here is my issue. I bought a 2011 used that had 57k miles on it last month. Never even knew it had a display to read the outside temperature because nothing ever showed, until yesterday.

I went through the car wash and just as it started I got a warning to watch for icy conditions on the road. Thought nothing of it until I left, and my AC would not work anymore. Pulled over and noticed the display read -39, and them -40 degrees F. I was about halfway home (30 mins) and the display of the temperature went away again, but still no AC working.

Fast Forward about 12 hours, and my A/C now works again, but the temperature is still not displaying anything. I am afraid every time it rains or something it will keep doing that. Anybody have any advice/help?


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## stanman13 (Aug 2, 2016)

The ambient temperature sensor is located in the left side foglamp housing (lower drivers side of the front bumper). I'd start by checking that it's still there and plugged in. It's possible the carwash may have dislodged something.

As an aside, the temperature reading isn't particularly accurate. There's a thread or two about it on the forum.


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## NickD (Dec 10, 2011)

AC is disabled by the ambient temperature sensor if the readed temperature is below about 35*F, -40*F will definitely disable it.

Sounds like you have connectivity problems, not new, my 70 Buick had the same problem.

Have to drop the front under bumper cover to get at it, and as said, located behind the left fog light or bezel. If that front cover is still there, is a used vehicle after all.

Sounds like it is erratic, has two terminals on the connector that more than likely corroded, can be cleaned and should be good to go again, or that sensor may have to be replaced. Let us know what you find.


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## chevrasaki (May 1, 2015)

Welcome to the forum! Sorry to hear you've been having issues.

That's very weird, I agree with the idea to check that the sensor is still plugged in.


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## johnclark12 (May 19, 2017)

Just an update. It started raining today and the sensor kicked in again at -40F. As I drove it slowly lowered by 1 degree every second until I got to about -5 Fahrenheit. When I stopped at the red light it shot back to -40 and when I started going again it slowly went down. Going to work with a friend to take off the bumper and mess with the wiring to see if its actually the sensor.

Dealership wants to charge $36 for the part and $79.99 for 1 hour (Looking at about $115), but since my A/C won't work again, I cannot really put it off for long. Will update when finished with this project.


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## NickD (Dec 10, 2011)

No need to remove the bumper, just that small front cover underneath.

Ha, OE fog light kit said to remove the bumper for installation. Only reason was two phillips head screws had to be inserted at the very end. Just used my 90 degree screwdriver, saved a lot of worthless work. Also had to unplug that ambient sensor from the old bezel, was plugged into the new one with a hole in it for the fog lamp.


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## obermd (Mar 3, 2012)

-40 means the wire is disconnected. Make sure the sensor is plugged in securely.


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## johnclark12 (May 19, 2017)

Another update:

We just took out the black cover as said above, and turns out there was nothing but a wire hanging... no sensor... I'm not sure if it varies by car or not, but it was a green and white wire with another connector attached to it.. I am assuming that is what I plug the sensor into?

Going in to Autozone tomorrow to see if they have any, at least online it shows up as an item


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## NickD (Dec 10, 2011)

Suppose the good news is that front under cover was still there, bad news is no sensor. Some guessed that connector was not fully plugged in, my guess with intermittent operation, was a corroded connector. One reason why your AC would operate occasionally, those two wires were shorting out, showing a higher temperature.

Buy any chance, does this car have fog lamps installed? One reason why that sensor could be missing. Where did you buy this thing from? If a dealer, where is my ambient sensor?

Purchased my Cruze new, dealer really hit me for dealer installed items, one in particular was so-called splash shields, said no thanks, saw your work, can't even put these thing on straight. What about those plastic tabs in your bezel, the sensor snaps into, are those broken off?


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## johnclark12 (May 19, 2017)

The sensor never shows anything unless raining or carwash, then it would show -40. See link for picture of car and sensor location:

https://i.imgur.com/YRjxZh3.png


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## johnclark12 (May 19, 2017)

Update:

The part arrived in the mail today and I was overcome with joy when the part fit perfectly and plugged into the wire perfectly. I would shortly find out it wasn't that simple.

Turned on the car and it gave me the ice warning and has been stuck on -40 ever since. I drove around for a solid 5 minutes to see what it would do and got no result. Guess we will see what happens when I leave for work in the morning. More suggestions are welcome, could it be the wiring that is messed up?


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## ChevyGuy (Dec 13, 2014)

It's possible that the contacts have a layer of corrosion that keeps it from conducting. But we know from experience that it frequently won't work at first and it takes awhile before it decides to display.


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## NickD (Dec 10, 2011)

Circuit and resistance versus temperature table, hope this helps.


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## johnclark12 (May 19, 2017)

Started my car this morning to go to work and was very pleased to see 52 degrees pop up on my display! Looks like it now works and what would have cost me $115 at a dealer cost me $18 and about 2 minutes of labor. Thanks everyone here for the help and assistance on solving and fixing the issue. Let's hope that I don't need to start a new thread on here again!

P.S. This forum also helped me realize why the driver side heated seat doesn't work (known car issue). Thanks again!


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## BrandoFisher117 (Mar 14, 2016)

Glad to hear our community could help!


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## chevrasaki (May 1, 2015)

Very glad to hear you got the issue solved, thanks for the update!


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## petem124 (Jun 15, 2019)

It's your outside temperature sensor located in the front left bumper. It"s either missing or needs to be replaced. If the connector is loose or the sensor is missing. You can cover the connector with a zip lock baggie and secure it with a rubber band in the mean time to keep it dry


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## Eddy Cruze (Jan 10, 2014)

petem124 said:


> It's your outside temperature sensor located in the front left bumper. It"s either missing or needs to be replaced. If the connector is loose or the sensor is missing. You can cover the connector with a zip lock baggie and secure it with a rubber band in the mean time to keep it dry


Yes this was fixed two years ago, but thanks for reminding us. I can't get enough of Old Sleepy Nick:rotate:


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