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The AC failed suddenly out of the blue, took it to the shop. They replaced the compressor and stated there are no leaks (after testing with dye). However, the AC now takes, on a hot day, 15 minutes to start to make the interior of the car somewhat comfortable. I took it back twice. The first time they recharged and sent me home again. The second time they said that by process of elimination, it is clear that the condenser also needs replacing. (At first they said there is no test to see if the condenser needs replacing; when I probed further, they said they could check the pressure at the input side and the output side, but there's really no need, because there are only three potential problems with the AC, the compressor, the condenser, and leaks.)

The weather report says we're in for a cool, rainy week coming up. Should I wait until the following week to take it for the condenser replacement, so as to be able to judge fairly whether the condenser replacement truly results in properly working AC?

In case you want to know about the car: 2004 Corolla. AC worked fine up until that sudden failure.

Pᴀᴜʟsᴛᴇʀ2
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aparente001
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2 Answers2

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It could be the climate control unit that is not operating correctly. They often have servo controlled flaps that control the flow of air over the heater and evaporator to adjust the cabin air temperature.

First thing to check is that the compressor is running. You should be able to identify the AC compressor in the engine compartment. It will likely have a clutch on the front of it that engages when cooling is turned on. Watch the pulleys turning (keep fingers away), then get someone to turn the AC on full. You will likely hear a click as the clutch pulls in. The front of the compressor clutch will then start spinning. It should keep turning and should not keep turning on and off.

Then check the refrigerant pipes that pass through the firewall into the cabin. You should find that one gets very cold and may even start to frost up. If it is getting cold I would then start suspecting the climate control unit in the cabin.

HandyHowie
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You can't just change a compressor and recharge. You need to at least change dryer and flush the system and in some cases you may need to change the expansion valve. See here for detailed information about compressor and replacement of it.

There are ways to check if parts of AC system is working properly. As you mentioned, this involves checking pressures and temperatures at high and low pressure sides. This may be too technical for your mechanic. When I got my AC repaired and it was making vibrations at very hot days, the just did vacuum/refill(recharge) again because they didn't know what was the problem since car computer didn't log any errors. facepalm :) See this: http://rechargeac.com/how-to/ac-system-pressure-chart

I think you should get your mechanics suggested repairs done right away and start testing. I am guessing they will give you more than 1 week warranty on work anyway, so why not get it done right away?

The problem I see here is that obviously they don't know the reason and they will keep changing parts until issue is resolved. So you shouldn't pay for the work unless the issue is resolved. The problem can be expansion valve, evaporator, incorrect refrigerant amount, condenser, clogged dryer or even a faulty compressor. I would definitely force them to check for pressures/temperatures or promise warranty on fix or free. Knowing what was originally wrong with your compressor may help.

Evren Yurtesen
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