So I have only had the car for a little bit and I was told the Air Conditioning does not work. I also noticed the outside temp display next to the milage also is blank. Do those two not working rely on eachother?

I bought one of those, FILL UR AC, cans and the system was full of 134a. I check and the ac clutch never kicks on. So u checked fuses and relays, all good.

Is there something I can check? Its getting cold but it bothers me not working on an effing 2009 car.

Any thoughts?

 

Yep, the outside temp sensor, by the drivers headlight. If it's bad or broken, the car thinks it's very cold out, it will disable the A/C compressor.

Usually you find the wires broken from previous damage to the area, can be as simple as repairing the wiring to the sensor to get it working again. Or the sensor may be missing, which I've seen on repaired crashed cars.

 

I know that when the coolant temp doesn't show its the thermostat that's not working properly and will cause the ac to not work.

Isn't the part that reads the outside temp the one behind the passenger headlight bracket? (close to the radiator). Also are fans turning on I've had experience where fans don't turn on and ac won't work

Also I hope you check your pressure in your lines before you stared to fill, you don't want to over fill/under fill that will also cause the ac to not work properly

 

Problem 1 - outside temp sensor.... completely unplugged. Plugged back in and the temp shows on the dash. 74*

Problem 2 - AC still not working. The system has 35psi in there and that is smack dab in the middle of the green ranges. The fans work cuz i just let the car sit here and idle and the fans kicked on no problem.

What could be the next issue?


By the way, thanks for the help

 

I made the mistake of thinking mine where working and only one side was working. Have you checked to see if the compressor is getting power?

 

Does your info center display the coolant temperature or does it say ---*?

 

That's what I said in my first post if it shows that then it's the thermostat ^

 

My dic shows everything perfect. The only value it was not showjng was outside temp but i fixed that with help in this thread.

And the reftigerant is in the green zone according to my gauges

 

You might need something better to check than that and that would be with some manifold gauges

 

Have autozone do a CEL check. They do it free. But before that, try disconnecting the battery for a few minutes and try again. Just remember this turns off the AC button so you'll have to push it again.

 

35 psi is when the compressor running. if it shows 35 psi when its not running. it has no refrigerant in it. it would have to be 3 degrees F outside to show 35 psi.

lets say your outside temp with a cold car is 75 degrees. when you put your guages on the system it should read 159 psi with the compressor off. search 134a temperature pressure chart. it tells you the psi related to what temp the ambient is.

add some refrigerant and if that is the only problem, the compressor should kick on, at first it will cycle very often, until the pressure gets stable in the green.

if you only have 35 psi, you most likely have a leak, unless someone accidentally let the refrigerant out.

low pressure switch has the compressor clutch off.

Dave

 

I have an OBD2/CAN code reader plugged in to my ALDL at all times. I have no codes. I even ran it this morning to ensure i dont have a code stored.

Im guessing that i have compresses air in the lines. Im going to evacuate the system then refill with 134a.... unless you have any other ideas to try. For god sakes.... its an 09

 

@dave - are you sure you are not thinking of kPa? On the gauge green is 25 to 45psi but the kPa is up there in the hundreds. At 55psi it is in the red and that is without the compressor on

 

yes i am sure. the guage indicates the correct pressure that should be read while the compressor is running. that is the suction pressure. or low side.

the compressor is basically a pump. it has a discharge side (output) and a suction side (input).

with the compressor off, the system should be equalized, if you had any liquid at all in the condenser you would read the related pressure on the temp pressure chart.

Temp vs Pressure Chart - 134a - AC Auto Repair Help Forum

match the temp outside with the pressure on the chart and thats what it should be while not running if you have refrigerant in the system.

looks like i was looking at the wrong chart yesterday, this one is correct. i was looking at degrees C

if you find 35psig on the chart it correlates to 39.96 degrees F.

so if it was 40 degrees outside when you checked, then it would be correct.

if it was 80 degrees outside, you would read around 86 psig on a set of guages. both sides, this is with compressor off.

Dave

 

@dave -

If you look back at your chart it is showing psiG/HG meaning it is in inches of mercury... if you do a conversion from your psig/hg to psi you see that 35psi converts to 71.26 psig/hg and that is perfectly in range on your chart.

Conversion - http://www.convertunits.com/from/in+Hg/to/psi

 

nevermind dude. i did ac work for over 10 years. just trying to help.

psig means pounds per square inch guage. meaning it corrects for atmospheric pressure 14.7 psi at sea level. i.e. the guage reads 35 psi its 35 psig.

14.7 psi - 0 psig.

once again, its supposed to be in the green when the compressor is running. unless its 40 degrees outside, your ac is severely low on refrigerant.

good luck with your fix.

Dave

 

im just saying your table is psig/HG meaning inches of mercury. 1 inch of HG is equal to about 0.49psi

Just look at your table man.

 

If your reading 30-40psi with the autozone gauge with the compressor not running you do not have enough refrigerant. System pressure should be somewhere around 70-100 psi depending on temperature when the compressor is off. Simple as that... The cheapo guage that comes with the can only works when the compressor is on

 

Tupp, you're misinterpreting the chart. The red is vacuum, which is measured in inHg. The black is positive pressure, read in psi(g). The psig/Hg" is just saying that the untis are switching between inHg and psi; it's NOT saying that the units are "psig/Hg"". That doesn't make any sense.