Corolla S 2001 Ac Performance - Toyota Corolla, Chevy Prizm (1998-2008)

Hi, I have a Corolla S 2001 since oct 2013 and for the first time I've had to use the AC and I think it's either broken, or has no power.

There's something that I always found weird, even with the AC turned off, switching the temperature in the Temp Knob will change the temperature of the air coming out of the vents (if I turn on the fan of course). Even when it was a little hot outside, if I set the temp knob to the coldest, the air coming out of the vents with NO AC turned on was way colder than the air outside; which I found weird cause I'd expect that if no AC is turned on, the air coming in would be as cold as the air was outside (or actually even warmer cause it has to go through pipes or whatever)

Maybe that's the way it works and it always has some sort of "AC" turned on all the time (which I'd like to know how it works cause if it is turned on is draining power)

The problem I have is that setting the temp to coldest, and TURNING ON the AC, doesnt change ANYHTING, I tried it for like 30 minutes with AC on, no changes, i turned off the AC to see if it changed, nothing.

I cant find my thermometer so I can't know for sure if the temp is changing, but I'm pretty sure it's not even changing 1 degree.

How does the AC button work? Is it possible I have something wrong with my AC unit? I know for a fact that it has never been fixed/recharged/upgraded since the car was manufactured neither by me or the previous owner (one of my best friends default_tongue )

I've read that recharging the AC would help get the air colder but before I even do that I want to understand how it works, cause right now, it feels like the AC button is just there for display default_tongue

Thanks in advance for the help I always get in this forum, I know I ask a lot of questions but I love my car and want to get it working as good as possible both performance and comfort wise

As for the vent blowing "colder" air - that can be normal - unless the car's interior is heat soaked, moving air will always feel cooler.

When you turn on the A/C - do you hear the engine revs bump up a bit? Hear the compressor kick on (should be a noticeable pitch change)? Does the A/C light on the button turn on?

Could be a number of possible issues for the A/C not working. Possible that the A/C unit is out of charge or low on charge. If low on charge, the compressor will not kick on (safety feature). Could be a bad relay, or other wiring issue. Could be a bad clutch or worn bearings on the A/C compressor.

They do make DIY recharge kits but I'm leery on suggesting those. As you could very easily overcharge the A/C system. That could result in leaks down the road / compressor damage / possible system contamination if you put in the wrong refrigerant and/or additive oil.

Best to have a HVAC shop take a look - as they'll have the equipment to check the high and low side pressures, check the system for leaks if it is low on refrigerant, see if the compressor seized up on you.

As for the vent blowing "colder" air - that can be normal - unless the car's interior is heat soaked, moving air will always feel cooler.
When you turn on the A/C - do you hear the engine revs bump up a bit? Hear the compressor kick on (should be a noticeable pitch change)? Does the A/C light on the button turn on?
Could be a number of possible issues for the A/C not working. Possible that the A/C unit is out of charge or low on charge. If low on charge, the compressor will not kick on (safety feature). Could be a bad relay, or other wiring issue. Could be a bad clutch or worn bearings on the A/C compressor.
They do make DIY recharge kits but I'm leery on suggesting those. As you could very easily overcharge the A/C system. That could result in leaks down the road / compressor damage / possible system contamination if you put in the wrong refrigerant and/or additive oil.
Best to have a HVAC shop take a look - as they'll have the equipment to check the high and low side pressures, check the system for leaks if it is low on refrigerant, see if the compressor seized up on you.

Thanks for the response.

Actually when I mean COLDER than outside, I mean like AC cold.

Yesterday the car was in the sun, I got into the car, temp reading was 93, turned on JUST the fan with the cold setting and the air coming out of the vents was indeed cold.

Actually now that you mention it, i don't see ANY diff when I turn on the AC (although the light turns on) but I do see the revs changing and some sort of "charging sound" as soon as I turn the fan on.

Could it be that when I turn on the fan, the AC is turning on regardless?

Yeah, I can see cooler - but not that cold.

If it is set to defrost - it will automatically kick on the A/C. Possible that the blend door is totally messed up - so it is diverting cold air away from where it should be. Mine did that when some Chipmunks decided to nest in the car, couple of winters ago. Car was in a garage - covered with a car cover, but they still got it.

Could try the different positions (floor, floor+vents, defrost+floor, defrost, etc) - with and without the A/C button pushed in - see which one has cold air blowing out the vents.

Yeah, I can see cooler - but not that cold.
If it is set to defrost - it will automatically kick on the A/C. Possible that the blend door is totally messed up - so it is diverting cold air away from where it should be. Mine did that when some Chipmunks decided to nest in the car, couple of winters ago. Car was in a garage - covered with a car cover, but they still got it.
Could try the different positions (floor, floor+vents, defrost+floor, defrost, etc) - with and without the A/C button pushed in - see which one has cold air blowing out the vents.

That's it then, the AC is turned on because the position is set to the defrost the windshield!

Ok so if it is working fine then it's definitely not enough to keep me cool under the california sun.

I'll keep playing around with the settings to see if I can get it to cool more, otherwise I'll take it to some AC place so they can look at it.

Thanks!

I was thinking and I think the only problem is that the AC was used a lot before I got the car so probably the charge is low.

If I buy one of those recharging kits with the gauge and follow instructions could I snip something up? or is it safe?

this looks pretty failproof

Although in most cases I've seen this used, they say the air is not cold at all, and in my case, it's that it's not cold ENOUGH but it is definitely cooling the air.

Possible that could help - the only thing that could cause issue is that you'll overcharge the system. AC refrigerant doesn't get "used up" - regardless if the system us used lightly or heavily - but it can leak out from weakened seals and/or damaged hoses in the system.

Normally, you'd need to hook up a pressure manifold to monitor the high side (high PSI) and low side (low PSI) ports of the system. The pressure gauge on those charging cans has very poor resolution - they will not always indicate pressure - just a gross range like: low charge, good charge, and overcharge.

There is a sight glass window on the accumulator of the AC system. Should be very close the radiator - just look for the large aluminum cylinder with a bunch of hard lines running from it. At the top, is a little window that lets you see the level of refrigerant in the system. Start the car, set and run the A/C in max recirculate mode - fans on high. Then look at the sigh glass window. If the charge is good - you should see a couple of bubbles walk by the glass. If there are a ton of bubbles or you can actually see the liquid refrigerant walk by - the charge is too low. Don't see anything, there could be a restriction in the system somewhere.

That said - those kits are pretty goof-proof. Just find the low side, check pressure range - then add a little at a time until you get cold air or the gauge reads high. Just keep in mine, if the refrigerant is low - that means there is a leak somewhere in the system. Charge could last all summer or leak out within a couple of days.