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Nothing... Yes, I've eyeballed the compressor clutch and it is not moving.
Please explain. Unless the belt is broken, the clutch assembly on the front of the compressor should be turning at all times when the engine is running. You should be able to see when the clutch kicks in (usually with a "click") and begins turning the compressor.
First get a gauge and check the low pressure side to see if you have refrigerant. All systems eventually leak. You cna get a gauge at autozone or Oreilleys and probably return it after using it. they call it tool rental, but it is not a rental, you just buy the tool and then return it. it is very easy to check. find you low pressure line nipple, remove the cap, slip the gauge nozzle over the nipple, turn on AC. Watch the gauge as the system cycles. the gauge normally has colors on it. green yellow and red. It will let you know if the pressure is high or low.
If the pressure is correct, then you should start checking electrical.
Already done. There is no pressure because the compressor is not running I assume.
Quote:
Originally Posted by High_Plains_Retired
Please explain. Unless the belt is broken, the clutch assembly on the front of the compressor should be turning at all times when the engine is running. You should be able to see when the clutch kicks in (usually with a "click") and begins turning the compressor.
I don't think that is correct. From what I have seen and read, if the compressor/clutch goes or is not active, then then belt turns but the clutch does not engage.
So, the belt is turning but the clutch is not engaging.
Already done. There is no pressure because the compressor is not running I assume.
I don't think that is correct. From what I have seen and read, if the compressor/clutch goes or is not active, then then belt turns but the clutch does not engage.
So, the belt is turning but the clutch is not engaging.
"No pressure"?
As in zero pressure?
If that's the case, then that's your problem.
Even without the compressure running, an a/c system that's charged will still have a significant amount of pressure. At 90 degrees F ambient temp, it should have the saturation pressure of 104 psi (more if the engine has been running and it's hot under the hood.
If it has zero pressure or close to that, then all your refrigerant has leaked out and the low pressure switch isn't allowing the compressor clutch to engage.
The A/C electrical circuit is a series of things that need to happen. When 12v makes it all the way to the end it triggers a relay, which closes and allows power to the compressor clutch. You should here a distinct "clink" when the clutch engages.
The series that it goes through should be something like this:
"constant 12v -> A/C pressure switch -> ECU -> dash switch -> relay coil" and at the end 12v reaches and activates the relay, closing it.
There may be more items in this series, but at minimum the dash switch must be on, the pressure switch must be closed, and the ECU must be passing the signal through. If this happens, 12v reaches the relay.
Some tests:
-Take the relay out, and stick a paperclip (or whatever) in the correct slots to send power on to the compressor clutch. This is basically bypassing the entire system and forcing the compressor on with direct battery power. You can do this with the engine off and the key in the 2 position and it should still engage - just beware of leaving it jumped with the engine running, as the pressure switch is not regulating system pressure. This rules out a few things, namely that the A/C relay has power to it and that the compressor clutch works. Depending on the results of this test, your troubleshooting can go in a few directions.
-If the clutch engages with the above test then for whatever reason the circuit which activates the A/C relay isn't fully closing - meaning you have an issue with the pressure switch, ECU or button on the dash. Most commonly it's low system pressure, so the pressure switch never closes. You can try jumping the pressure switch with a paperclip as well and see if you start getting power at the relay coil.
Having an electrical diagram helps with this troubleshooting tremendously.
Please explain. Unless the belt is broken, the clutch assembly on the front of the compressor should be turning at all times when the engine is running. You should be able to see when the clutch kicks in (usually with a "click") and begins turning the compressor.
The clutch only kicks on when told to. It does not constantly rotate. However the AC pulley does turn constantly if engine is running.
Quote:
Originally Posted by jobaba
Already done. There is no pressure because the compressor is not running I assume.
I don't think that is correct. From what I have seen and read, if the compressor/clutch goes or is not active, then then belt turns but the clutch does not engage.
So, the belt is turning but the clutch is not engaging.
If there is no pressure that means you have no Freon. System under pressure regardless of compressor running. Which means you must have a hellacious leak or blown seal
So, the belt is turning but the clutch is not engaging.
Got it. I should have been more clear to say the clutch pulley is turning at all times.
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