Carrier A/C not cooling
#1
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Thread Starter

Hi, I have a Carrier A/C model 24ABB324W310 which was installed new in 2012. The unit comes on when called for but, the air is not cooling. I visually checked the capacitor which appears to be ok without being puffed up. I believe the A/C wouldn't come on if the capacitor was bad. Anyone have any suggestions for further troubleshooting? Any help would be most appreciated. Thanks, Ray
#2
You need to go outside and check the outside unit (compressor/condenser) to see if it's running. My guess is that it's not, which is why it's not cooling. Since you said you visually checked the capacitor, you must have removed the cover(s) from the unit. Inside, you'll see the contactor, which is a relay. It's rectangular in shape and usually has 2 heavy wires attached at each end and thinner wires attached to contacts on the sides of the contactor. With the power to the outside unit turned on, take a piece of wood and push in on the top of the contactor. There may be a "button" making it easy to push the contacts down. This will close the contacts. If the outside unit turns on, you're likely losing the 24VAC control signal that tells the contactor to turn on. To proceed further, it will be very helpful if you have a multimeter and know how to use it.
#3
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Thread Starter
Thanks for the reply....... Yes, there is a button in the center. I pushed the button and it turned on while holding it in. I also viewed the relay when I turned it on by using the thermostat. The A/C came on and the button was automatically pushed in. Is this the correct operation of the relay? Thanks again for your help. Ray
#4
Yes... the thermostat holds the contactor in.
So now the contactor is in..... is the A/C working ?
If no.... is the fan in the condensor running ?
Is the compressor running ? Feel the large copper line exiting the unit.... is it cold ?
So now the contactor is in..... is the A/C working ?
If no.... is the fan in the condensor running ?
Is the compressor running ? Feel the large copper line exiting the unit.... is it cold ?
#5
Member
Thread Starter
Thank you for the help.......
So now the contactor is in..... is the A/C working ?
The A/C unit is on but, no cold air.
If no.... is the fan in the condensor running ?
The large fan is running on the A/C unit.
Is the compressor running ? Feel the large copper line exiting the unit.... is it cold ?
No
Thanks again for helping me out. Ray
So now the contactor is in..... is the A/C working ?
The A/C unit is on but, no cold air.
If no.... is the fan in the condensor running ?
The large fan is running on the A/C unit.
Is the compressor running ? Feel the large copper line exiting the unit.... is it cold ?
No
Thanks again for helping me out. Ray
#6
If the compressor and condenser fan are both running, but the large copper line isn't cold, it would appear that the system is very low on refrigerant. If that's the case, you have a leak somewhere in the system. The leak will need to be repaired before more refrigerant is added, otherwise it will leak out again. It's time to call a qualified A/C technician.
#7
Member
Thread Starter
It's a shame........ This unit was installed new in June of 2012. As for warranty, the compressor has a 10 years, not including labor. Thanks, Ray

#8
Actually..... if it was low on refrigerant the fan and the compressor would both be not running.
It sounds like the fan is running but the compressor is not. That could possibly be a capacitor issue.
It sounds like the fan is running but the compressor is not. That could possibly be a capacitor issue.
#9
Hi Ray,
Does it sound to you like the compressor is running as well as the outdoor fan motor?
I doubt that an entry level condenser like that 13 SEER Carrier would have a low pressure switch. It could be very low on refrigerant but you would usually see oil somewhere if a large leak suddenly occurred and you often see ice if the leak is not extreme. Water in the pan under the evaporator ( indoor) coil might also be a sign that you lost refrigerant.
Capacitors often don't look very swollen when they fail.
I still knew at a glance that the capacitor on the right would measure 0 microfarad when I removed the service panel.
Does it sound to you like the compressor is running as well as the outdoor fan motor?
I doubt that an entry level condenser like that 13 SEER Carrier would have a low pressure switch. It could be very low on refrigerant but you would usually see oil somewhere if a large leak suddenly occurred and you often see ice if the leak is not extreme. Water in the pan under the evaporator ( indoor) coil might also be a sign that you lost refrigerant.
Capacitors often don't look very swollen when they fail.
I still knew at a glance that the capacitor on the right would measure 0 microfarad when I removed the service panel.

#10
Member
Thread Starter
Actually it sounds like just the fan...... hard to tell. I cleaned the A/C unit coils and inside area, everything was bone dry. There is a slight hum sound that lasts for about 5 seconds and repeats itself approx. every 3 minutes or so. I have a cheap digital multimeter in which I have never used. Would this slight hum be caused by the capacitor trying to tell the clmpressor to come on? I sincerely appreciate your help. Thank you, Ray
#11
It's possible that the compressor capacitor is bad. I thought you said that both the compressor and condenser fan were running. If you put your hand on the compressor, you should be able to "feel" if it's running. Capacitors are cheap enough that it's worth replacing the capacitor to see if that solves the problem. If your unit uses a dual capacitor, the compressor side will be the larger value (usually in the range of 40-50 mfd).
#12
Member
Thread Starter
A HUGE THANK YOU!! Just got back and installed it. Working like a charm! I could see that the bottom was slightly puffed out once I removed it. I did test it also which showed it was defective. You hit the nail on the head..... $20.00. Again, THANK YOU for all your help and thanks to all of you that pitched in as well! Ray