A/C leak

2003 CHEVROLET SILVERADO
246,000 MILES • 5.3L • 4WD • AUTOMATIC
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HD2424
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Back history: I had an electrical problem with my A/C system. I had evacuated A/C system and it had -30 of vacuum on gauge held for over an hour so I had no leaks. I went to charge it, and nothing happened. I tried to jump relay for the A/C compressor, and nothing happened. By this time, I had put two cans in. By this time, I had put two cans in. I stopped, I changed the engine harness because of that and some other electrical problems. The truck is running fine now.

Now it’s all ready to charge but from the system not working previously there is a leak.

My question is, how should I find leak? I have light and an A/C leak detector. Do I need to put more oil?
From pressure building up when A/C compressor was not working where most likely do you think leak occurred. Just need some direction how to proceed.
Apr 27, 2022 at 5:48 AM
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KASEKENNY
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I am not sure I understand. You said that you pulled it into a vacuum, and it held for over an hour. If this is the case, then the system is sealed and does not have a leak.

Is there another reason that I missed that you suspect there is still a leak? I understand the compressor is not coming on but that is not only caused by a leak.

So, if you jumped the relay and it still did not come on then you may have a failed compressor.

However, to provide the info you asked for, here is video that shows how to find a leak:

https://youtu.be/yrhWKlQEPWw

What I would suggest is we just hook up a gauge set and find out what the pressure is in the system.

https://www.2carpros.com/articles/re-charge-an-air-conditioner-system

Then we can check for voltage at the compressor and if you have 12 volts when it is turned on then the compressor has failed if it is not coming on.

https://www.2carpros.com/articles/how-to-check-wiring

I attached the wiring diagram below.

Please run through this and let us know what questions you have.
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Apr 27, 2022 at 6:25 PM
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HD2424
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Okay, I’ll do those checks and let you know. thanks
Apr 27, 2022 at 7:06 PM
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KASEKENNY
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Sounds great. Thanks for the update and I am curious as to what you find.

If the compressor runs or not when you put power to it, then that will put us on the right path so let me know if you have questions about doing this.

Thanks
Apr 28, 2022 at 6:35 AM
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HD2424
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Okay, will do.
Apr 28, 2022 at 7:50 AM
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HD2424
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Update: I found leak and fixed it.
I evacuated system and charged the system. I jumped A/C relay to start the compressor it took a little Freon. The compressor was turning but no Freon going through. My low side pressure was high and high side low. I ohm out compressor and it was good. Could a new compressor still be bad even though it ohms were correct?
May 21, 2022 at 3:17 PM
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KASEKENNY
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Short answer is yes. Just because the internal windings are ok in the compressor does not mean the seals inside of it are okay, and can build pressure.

Basically, if the compressor is turning but not pulling in freon or building pressure then the compressor has failed.

Take a look at this chart which will explain this. You will see that the low side high and high side low points to a faulty compressor.
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May 21, 2022 at 4:27 PM
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HD2424
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Okay, that’s what I thought.
May 21, 2022 at 4:58 PM
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HD2424
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Thanks, I’ll return compressor and try another I’ll update you.
May 21, 2022 at 4:59 PM
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HD2424
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Thanks I’ll return compressor and try another I’ll update you
May 21, 2022 at 4:59 PM
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KASEKENNY
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Okay. Yeah. I am not sure I was aware this was a new compressor but if it were then I agree, returning it and getting a replacement would be what I do based on this info.

Thanks for the update. Let us know how this turns out.
May 22, 2022 at 5:30 AM