intermittent A/C compressor clutch not working properly?

Hi,

The idea that the compressor engages when the engine RPMs increase makes me think it is low on Freon. However, I need you to explain what was meant by the engine revs by itself.

As far as charging it, here is a link that explains how it's done. Since it is unlikely that you have a system to evacuate and recharge the system, this will help us identify if the pressure on the low side of the compressor is within spec.

https://www.2carpros.com/articles/air-conditioner-how-to-add-freon

Additionally, here is a link you may find helpful as well:

https://www.2carpros.com/articles/car-air-conditioner-not-working-or-is-weak

Let me know what you find.

Take care,

Joe

Hi, since I asked the question, here is what I have done and think I know. I went ahead and replaced the relay in the fuse box, the one it it looked like one the 5 contacts had broken off, that did not make any difference in what was happening. I thought the same thing about low on Freon, I got some getting ready to try to recharge it myself, watched more videos on YouTube and saw the gauge that came with the Freon can said I had too much, and one video said do not use stuff that is supposed to seal leaks. So, I did not recharge the freon. I did get the Freon to an acceptable amount according to the Freon gauge that came with the can and that did not seem to help either. I went ahead and got a new low-pressure switch. I do believe that is the only thing that changed anything I was seeing, still hot air coming out but now the compressor clutch was never engaging, and the engine was not revving up (I mean engine idle speed never goes higher, like someone is in the car giving it a little gas). Hope that helps. I'm now at a loss as to what to do next. I was going to view the videos you sent me and then try switching the old relay and the old low-pressure switch to see if either of those caused the compressor clutch to stop engaging and the engine to stop revving up on its own. I plan on trying to return the can of r-134a I had gotten to recharge the system, but that has the only gauge I have the helps me know the level of Freon. I look forward to your next reply and thanks for helping!

Hi,

When you had the gauge on the system, was it too high? Also, the engine RPM increase at idle is to prevent the engine from stalling with the added load of the compressor. Are you sure the relay and fuses in the vehicle presently are good?

Joe

Yes sir, it was in the red. That was with the engine off, with engine on it would go from high to low, back, and forth. It currently stays in the mid green area at all times engine off or on. The engine RPM would increase, and compressor clutch would spin and then decrease and stop spinning, it would repeat that every few seconds. After getting the gauge in the green the compressor clutch never spins. I replaced the relay and the low-pressure switch, and checked the two ten-amp fuses, all of that seemed to be in good shape. Kept the old parts, just in case. I also have a 1990 Silverado and just thought maybe I could pull parts off of it as well if I need to, not worried about the A/C on that truck. I think those parts should be interchangeable.

Hi,

If it originally went into the red with the engine off, it sounds like the compressor is bad or it is overcharged. With the engine off, the pressure should equalize. Also, it shouldn't be jumping from high to low.

What was done to keep it in the green? Also, is there a way you could get your hands on an A/C manifold set of gauges? I need to know what the actual low and high-pressure sides of the system are reading. Additionally, the outside temperature when checked is needed as well.

Take a look through this link. It shows the gauge set I'm referring to.

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


Joe

Let me know.

I do believe it was overcharged and I let freon out until the gauge I had said it was in the green, which I think it was between 40 and 50 PSI on the gauge and outside temperature would have been mid to upper 90s. I just tried to check again to give you a little better and more accurate info, but I got no pressure reading off that gauge at all, engine on or off, and nothing activating the compressor. I now have something more pressing going on with my daily driver, and that has to be resolved before I can put much more effort into this A/C problem. I was going to put all the old parts back on and see if that changes anything, but all my tools are in my daily driver and currently not with me. The no pressure at all has me puzzled and I at least have to get freon with no leak stuff just to make sure I don't do more damage until I know it has a leak. That is where I am at the moment.

Hi,

Certainly, you have a leak. Also, if the system was overcharged, it wouldn't work properly. By any chance, did you add PAG oil to the system?

Let me know.

Joe

no sir, I have not added anything. What do I need to do next? Add Pag oil and the r-134a with leak sealer and go from there? It is an 18oz can. Can I ask how it was overcharged if it has a leak?

Hi,

If nothing was opened, the oil should be fine. As far as being overcharged, there is only one way that could have happened. If you checked before it leaked, it wouldn't have gone down. This is only a theory.

Joe

Okay, should I add the R-134a with leak stop and see what happens or find R-134a without leak stop? The only thing I opened was when I let Freon out to get it from red down to green on the gauge and when I changed the low pressure switch, I heard a little come out.

Hi,

Since we suspect there is a leak, I would use the one with the leak stop.

Let me know.

Take care.

Joe

Hi, I am back at it today, I think from what I have learned so far I am just going to add a small can of just R-134a and go from there. Will keep you up to date on how it goes after that.

Hi again, I felt cold air! Now I have to wait and see if it does have a leak or not before trying to return the freon that had leak stop stuff in it too and go from there. I did not need a new relay and will check and see if I needed a low pressure switch, if not I will try to return both of those as well. Will keep you up to date as I go if you want and thanks for all your help. Hopefully I know enough to go from here.

Ok, maybe 1 more question, it got to about 30psi, in my mind that is good enough, but should I go further and just never go over 50psi?

Hi:

A good low pressure reading has to be based on the outside temperature when tested. If you have 30 psi, I would think the ambient temperature would have been under 70 F when tested. Is that the case? If not, let me know what the temp was when checked.

As far as 50 psi being a max, once it reaches approx 85F degrees or higher outside, it can reach 55 psi. I wouldn't let it exceed that.

Let me know the temp when checked.

Take care,

Joe

Thanks, I keep forgetting the outside temps affect the psi readings. It was roughly 90 degrees when I added the 12oz can, psi went from 0 to barely above 30. Roughly my temperature was 90. I did go back shortly after doing that and the the psi had dropped a little and the clutch wasn't staying on the whole time. I then tried to make sure I finished off the entire can , it never went much past 30 psi so I figured that was all the can was going to do. What psi should I aim for when it is 90 degrees? I basically am stuck between 80 to 100 degrees for a good while. I foresee me asking if there is a leak, should I let it all out and then use the whole can with "leak sealer" or just use part of that can once I am certain it has a leak some where? Thanks again

Hi,

If the ambient temperature is approximately 90F, I would expect the low pressure to be somewhere between 45 psi and 50 PSI.

I would rather see you use only the freon with stop leak. Hopefully, that will take care of the issue.

Here is a link you may find of interest:

https://www.2carpros.com/articles/air-conditioner-leak-detection

Take care and let me know how things turn out for you.

Joe

Hi, I'm at a loss as to what to do again. I waited for the temperature to get to 90 and was going to get the PSI up to 45 or 50 like you recommended. I checked with engine off and it was well over 50 PSI, turned engine and A/C on and still well above 50. What am I doing wrong? I expected 30 PSI or less. I do have to jump start the compressor clutch to make sure it is constantly moving when I try to add freon. I never felt any cold air coming out as well.

Hi,

When the system is off, the static pressure will equalize, so higher pressure with it off doesn't surprise me. When it was on, what was the low pressure? Also, wasn't it just 30 PSI the other day?

Let me know.

Joe

Yes sir, it was just 30 PSI and then you told me it needed to be 45-50 on a 90-degree day, but when I tried to add more to get it to at least 45 it was saying it had somehow gotten well over 50, even with engine on and A/C running. Low pressure is the only pressure I can currently test.

I tried again, got cool air again, only got to about 35 PSI, going to go get some more freon now to try to get it to 45 or 50 PSI. I think a good bit of my problem is lack of experience and understanding of PSI. I 'll let you know more once I get it to 50 PSI.

Okay, it is 92 degrees, am very close to 50 PSI, all out of Freon. The A/C is currently working well, and compressor clutch working without having to "jump start" it. All appears to be working properly and I guess the next thing to do is wait and see if it leaks and when the A/C stops working again. Two of the bigger cans I used claimed to have leak sealer, etc. If the PSI does not stay where it is I guess the next thing is to add leak detector? Anyway, that is my current update.

Hi,

I hope it continues. Let me know if things change. Also, here is a link you may find helpful if it does:

https://www.2carpros.com/articles/air-conditioner-leak-detection

Let me know how things turn out for you.

Take care,

Joe

Hi, I checked it this morning and it was almost 50 PSI and working good. I then checked a while later when it was 96 degrees and it was almost 60 PSI, but all still working good. Will check again Sunday and keep track of temperature and PSI until something changes or goes wrong. After I got it up to almost 50psi it seems to be properly working and will hope it continues to do so. Thanks for your advice and help!

Hi,

That's good news. Keep an eye on the pressure. It shouldn't go much over 55 psi even up to 110 degrees. If it starts climbing, you may have a little too much freon in it.

Thanks for the update. Let me know if it continues for you. Also, please feel free to come back anytime in the future. You are always welcome here.

Take care,

Joe

Hi, I've been checking in the morning and then later in afternoon and I'm not seeing anything that gives me any concerns that there is a leak. 45 PSI in morning and almost 60 PSI in afternoon. Haven't noticed anything to make me think it is losing anything. I guess I should drive the truck a little more and use the AC to make sure it doesn't leak, and everything keeps working while in use. Thanks for all your advice. I should be good to go till something I can't easily figure out on my own comes up. Thanks again!

Hi,

You are very welcome. I'm glad to hear it's continuing to work and not lose pressure.

Please feel free to come back anytime in the future if you have questions. You are always welcome here.

Take care,

Joe

Hi, I am back with a different problem and not sure if I can continue on here or do I need to start the process all over. It is with a 2005 Avalanche and one back wheel has started locking up, not all the time, I want to say only when the brake pedal is touched. I pulled the wheels off to see if I could see anything obvious and sure enough one of the bolts holding the brake caliper on was missing. The brake caliper was loose. I figured I would ask. I'm really hoping it is easy enough to find that bolt, put it in and all be back to normal. I will now go see if I can find a replacement bolt and see what happens after that.

I put the bolt in, and test drove it a little. Did not act up at all and I think it is now good to go. Just had to ask because I like to make sure, and my experience only goes so far.

Hi,

Sorry to get back to you so late. Yes, that certainly will cause the issue. If you replaced the bolt and it is working well, it should be fine. However, just keep an eye on it to make sure it doesn't come loose again.

Let me know if things change.

Take care,

Joe

Hi, I'm back again. A/C is leaking. It got back to not working. I'd like to figure out how to fix it. I'm about to add 18oz of R-134a with leak sealer. Do I just fill it up, turn the truck off and check it daily/weekly, or should I let truck run for a while? Is there a way to help the leak sealer work better? My next plan was to add something with a dye in hopes of seeing where the leak is at. Thanks again for helping me to learn about car A/C systems.

Hi,

As far as the sealer, there is nothing different you can do. At this point, rather than trying the leak sealer, I would recharge it using a dye. Once it's recharged, you can check a few different ways.

If you use a dye, then a black light can be used to locate the leak. Also, you can even take a spray bottle and mix water and dish soap in it. Then, you can spray different connectors and components. If there is a leak, it will likely cause the soapy water to bubble.

Take a look at this link. It explains different options.

https://www.2carpros.com/articles/air-conditioner-leak-detection

Let me know if this helps or if you have other questions.

Take care,

Joe

Hi, just giving you an update. I just tried to put AC Pro Stop Leak Super Seal but don't think anything even came out of that cannister, I added more R-134a with leak sealer and ran the truck for 20 minutes. With everything on I got a little more than 20 psi reading and with everything off I got a 45 PSI reading. 77 degrees outside. My plan is to return the Ac pro stop leak super sealer and try the super tech version and go from there. I'll worry more about finding the leak after keeping track of the psi over the next couple of weeks.

I also have a 99 Corolla that will probably need a radiator replacement soon. In looking for a radiator for it, my question is does it matter if the radiator is set up for automatic transmissions or not. All I seem to find is radiators that have 2 connections for automatic transmissions at the very bottom. My assumption is that will work, I just don't connect anything to those two ports, but my fear is the dimensions might be different and somehow not properly fit my manual transmission, Corolla.
Thanks for all your help.

Hi,

Thanks for the update. As far as the radiator is concerned, if you have a manual transmission, it should work just as you described it. The AT connections will not be used. If possible, however, I would plug them. There should not be a coolant leak, but if your luck is like mine, anything can happen. LOL Also, the dimensions should be the same.

Take care and let me know how things turn out.

Joe