JohnHere wrote: ↑Tue Aug 20, 2024 7:45 pm
I think you're right that the system is getting the proper electrical signals to run. Additionally, if the pulley on the front of the compressor is turning with the engine running, then the compressor itself is also turning since it's directly driven by the engine and doesn't have a clutch (if my information about the car is correct). The two wires you mentioned should connect to the control valve at the back of the compressor.
It's possible that the compressor is stuck at minimum displacement and therefore, not pumping anything, due to a faulty control valve, which can be replaced separately. Or the compressor itself could have destroyed itself internally if it was run with a low charge and/or not enough oil.
I also want to mention that I did a vehicle system code scan of the vehicle and the one system that did come back with no issues was the AC system. I did not have any codes stored for it. The codes that were stored were for some ABS sensor issues and a Catalyst code for potentially a bad catalytic converter. None of these should affect the AC operation. I did get under the car and inspect the wiring from the compressor connector to the control valve and it all looked intact with no damage.
Most AC systems have safeguards in place so that the AC compressor will not activate if the charge is too low. I'm not sure on this vehicle though. That is why I did the code scan to make sure there were no AC related codes that could have possibly disabled the system until the codes were cleared and any issues fixed.
Good idea to scan it for codes and glad none showed up for the A/C system.
It could be low on charge but not quite low enough to trigger the trinary switch threshold and shut down the system. Run it like that long enough and the compressor will be "starved" for oil, eventually ruining it. Just like an engine that's run with insufficient motor oil and that eventually seizes.
How much mileage has this car logged?
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JohnHere wrote: ↑Tue Aug 20, 2024 8:40 pm
Good idea to scan it for codes and glad none showed up for the A/C system.
It could be low on charge but not quite low enough to trigger the trinary switch threshold and shut down the system. Run it like that long enough and the compressor will be "starved" for oil, eventually ruining it. Just like an engine that's run with insufficient motor oil and that eventually seizes.
How much mileage has this car logged?
The car has about 186,500 miles on it so quite a few. The compressor is obviously not seized, or it wouldn't be turning but it could be worn out and not building any pressure or as you mentioned, the control valve may be bad. With as many miles that are on this car, it probably would be better to just replace the compressor and probably the condenser. I will have to talk to the owner and see if he wants to go any further on repairs or just live with it like he has been doing.
I'm also replacing the driver's door window motor because it will go down fine but starts and stops going up. He did mention that if I could fix that, he might not worry about the AC. This car is just an extra vehicle for him and his wife so not a daily driver.
With that much mileage, it's a good idea to replace the compressor assembly with a new one (not a rebuilt unit). The original compressor has been running along with the engine since the car was new, so I'm sure it's gotten a bit "tired" by now. The new compressor comes with a new control valve as well.
Pour out, measure, and closely examine the oil from the original compressor because you'll need to add-back the same amount into the new compressor. If the old oil is transparent, light-to-medium amber in color (not black), and it doesn't contain any metal shavings and/or plastic particles, then you probably don't need to replace the condenser unless the compressor manufacturer requires it for warranty purposes. However, I would install a new R/D desiccant kit, which should be done each time the system is opened.
I believe the OE for this car's A/C system is Denso.
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JohnHere wrote: ↑Tue Aug 20, 2024 10:11 pm
With that much mileage, it's a good idea to replace the compressor assembly with a new one (not a rebuilt unit). The original compressor has been running along with the engine since the car was new, so I'm sure it's gotten a bit "tired" by now. The new compressor comes with a new control valve as well.
Pour out, measure, and closely examine the oil from the original compressor because you'll need to add-back the same amount into the new compressor. If the old oil is transparent, light-to-medium amber in color (not black), and it doesn't contain any metal shavings and/or plastic particles, then you probably don't need to replace the condenser unless the compressor manufacturer requires it for warranty purposes. However, I would install a new R/D desiccant kit, which should be done each time the system is opened.
I believe the OE for this car's A/C system is Denso.
You are correct. I have found information that Denso is the OEM supplier for at least the compressor. The only reason I mention replacing the condenser is that my research has shown that these are prone to leaking after they get some miles on them and they are not that expensive to purchase and replacement doesn't seem to be too difficult from the video that I watched.
I want to thank you for all of your help. I will report back if he decides to fix the AC and what the results were.
A parallel-flow condenser also acts as a filter of sorts and will partially clog if the compressor disintegrates internally and sends its debris downstream. In such a case, the condenser will definitely need to be replaced, which is why I asked about the presence of metal and plastic particles in the oil and its color.
Usually, a condenser won't fail mechanically unless some kind of road debris kicks up and damages it, or it corrodes-through due to the chemicals used to melt ice and snow on roads in the winter (if you live in such a region).
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The compressor does have some corrosion on it along with other aluminum parts on the engine. The car was bought in Kentucky when they lived there and is now in Missouri.
They have decided to not fix the AC since the car is just an extra vehicle and is not used all of the time and summer is about over. They just want the driver's window fixed so they can roll it down when needed. They said that they might fix the AC next year.
Sounds good. Come on back should the owners decide that they need a working A/C system in the car. I know from experience that Missouri is humid as all get-out, so it'll probably be next summer when the heat and humidity rise to intolerable levels
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I sure will. They have the car back now and are just glad that the driver's window now works as it should. The car has some other issues and codes stored in the computer which they are not concerned about so I doubt the AC will ever be fixed. Thanks again for all of the help.
