A/C stopped blowing cold, not sure compressor is running at all

2001 MITSUBISHI ECLIPSE
207,000 MILES • 2.4L • 4 CYL • 2WD • AUTOMATIC
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KIWASABI1
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Well, it seems my car problems aren't over just yet. Today on a fairly long drive I noticed my A/C wasn't blowing any colder than the fan. This was strange because it wasn't particularly warm out, probably 75-80 degrees Fahrenheit. It's late and dark so I haven't had a chance to check to see if the compressor is spinning at all. But I noticed that when I turn the A/C or defogger on, there does not appear to be an extra load on the engine and the RPM's don't raise from the IAC. The RPM's just hold steady. At first I figured I just needed more refrigerant since the car is 20 years old and has never been recharged with R-134A. But now that I notice the RPM's no longer adjusting while idling and turning on the A/C, I suspect the A/C compressor or clutch. What do you guys think?

BTW I've been having a very slight overheating issue cropping up while idling or slow moving driving with lots of stops and starts. The thermostat will hover slightly above halfway, then go back down eventually as the fan kicks on I guess. After this happened, the gauge is now filling up a lot more in these circumstances to more like 75%, then coming back down eventually. My question is, does my A/C compressor pulley also run my water pump, and thus the issues could be related? My experience here is I had an A/C compressor go out on my old Saturn years ago (which had lots of noise when the A/C compressor was on BTW, which my current car doesn't have). When it finally stopped working completely, I lost power steering and my car started overheating because the A/C compressor belt ran the power steering and water pump. So I'm curious if they're connected in my car as well.

I'll reiterate here that there are no loud noises, it seems now that the A/C compressor is not engaging at all. I will have to check it and report back tomorrow whether it's spinning or not.
May 30, 2020 at 11:02 PM
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KIWASABI1
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Probably just disregard the second paragraph. I seem to have mixed up when my alternator went bad with when my AC compressor went bad on my Saturn. Obviously the AC Compressor isn't spinning when it isn't on, so it's not driving the water pump and power steering. Forgive me as this was 16 years ago. For the overheating issue I suspect water pump or thermostat, since the radiator is 9 months old and there are no coolant leaks or white smoke from burning fluid.
May 31, 2020 at 3:06 AM
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ASEMASTER6371
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Good morning,

Do you have a set of gauges to give me the high and low side readings of the system?

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

Do you have a voltmeter or test light to do some testing? I want to see about testing power to the compressor.

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

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Roy
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May 31, 2020 at 3:56 AM
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KIWASABI1
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I don't have the A/C pressure gauges. I can borrow a multi-meter. Question: If the A/C compressor/clutch aren't spinning at all, that eliminates the refrigerant as the issue doesn't it? And if the electrical connector tests fine then it's definitely the compressor?

Stupid question, but any chance I can whack it with a hammer like you'd do with a starter and get it moving again? Or any other hack tricks to try like that before replacing anything?
May 31, 2020 at 9:06 AM
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ASEMASTER6371
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Low or no refrigerant will cause this issue. That's why I need to know the pressures.

There will be no voltage to the compressor unless proper Freon is present. We also need to test for proper voltages to all the components.

Roy
May 31, 2020 at 9:14 AM
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KIWASABI1
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Really? Then I'm buying the recharge kit with the gauge on it and going to test the r134a level. I suspected the refrigerant from the start. But since the compressor stopped kicking on at all I presumed a more serious problem. I apologize for being such a hack mechanic. But I've heard always start with the simple things. Being out of refrigerant after 20 years makes the most sense to me, especially since I think I noticed a gradual decrease in cooling ability over the past month or two.
May 31, 2020 at 9:20 AM
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ASEMASTER6371
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I understand.

Keep me updated with the results.

Roy
May 31, 2020 at 9:36 AM
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KIWASABI1
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So today I went to recharge the A/C system, and noticed a broken wire connected to the A/C Compressor (see attached pictures). I believe this is the Refrigerant Temperature Switch according to the repair manual. It's a one wire connector that plugs into the A/C Compressor. There is a separate 2-wire connector which must be power and ground. So this must be the signal wire I assume. Anyway, from the help of a friend, we tinned up both sides of the wire, soldered it back together, added a little duct tape, and the compressor started working again! So that's the solution to this question.

Since I already bought the R-134A recharge kit, I went ahead and did that too since it was a little low as well. I'm a little paranoid that I overfilled it because the gauge is jumping around a lot. I realize it's supposed to read high when the compressor is off, and gives an accurate reading when the compressor is on. But I was getting varying readings while the compressor was running too. Does it take a while for the fluid to circulate or something before it reads accurately? It was reading as high as the yellow area of the gauge (50-60 PSI) while running, and finally settled back around 35-40 (the green area is 30-50 PSI). I'm going to recheck this again in a day or two and see what it says then. I want to be sure I did not overfill it, and thus could cause damage to the compressor.
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Jun 3, 2020 at 5:18 PM
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ASEMASTER6371
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The high side reading should be 2 times ambient temperature plus 15%.

The low side should be 25039 pounds, rock solid. It should not vary at all.

Roy
Jun 3, 2020 at 5:26 PM
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KIWASABI1
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Low side is what the kit has me check and plug into. The gauge goes from 0-150 PSI, which 30-50 PSI being green, 50-60 being yellow, and 60-150 being red.

One thing I forgot to do was have recirculate activated, which I know drops the reading further. I've noticed my compressor is kicking on and back off a lot while idling, I notice the RPM's going up and down from the IAC. When I'm driving, sometimes the A/C is blowing very cold, other times it's kinda warm. So something is still not quite right here.
Jun 3, 2020 at 5:47 PM
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ASEMASTER6371
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What is the reading on the gauge when the AC is operating?

Roy
Jun 3, 2020 at 5:55 PM
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KIWASABI1
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See attached video. This is with the A/C set to maximum with recirculate "on". When the compressor is off, it's at 60 PSI. When it turns on, it's around 50. Which evidently is about right on an 80-90 degree day, you're supposed to be at about 45-55. But I suppose my problem is how the compressor is constantly cutting off and on. When it's off and the reading is at 60 (which as you see, is most of the time) it is blowing warm air. When I first turned the car on and it wasn't as heated up, the A/C was blowing very cold and staying on. Once the car got hotter, the compressor constantly cuts out like you see in the video. It would seem there's another problem now unless I'm missing something.
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Jun 3, 2020 at 6:31 PM
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KIWASABI1
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Found this comment when digging around. Which 50 psi seems to be where i'm sitting at. So it would seem it's not overcharged. But since i can't verify the high side, difficult to say.

" The CAN is done for safety and it's only at 50 psig. So "normal" people can't get blown up or sue them for damages. I have tried it and tested and it's always neutralized /balanced itself out at 50 psig. Yes, i have tried to overfilled the system, but it won't allow me to do so because there is a limit and balanced due to the pressure in the can itself!"
Jun 3, 2020 at 6:50 PM
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KIWASABI1
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I guess I'll need to get the high side gauge to find out what's going on for sure. Probably going to have my mechanic run the test unless you've have any other suggestions. From doing some reading, it's either undercharged or overcharged most likely.
Jun 3, 2020 at 7:31 PM
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KIWASABI1
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Doing some more reading, sounds like I may have added too much air to the system and need to bleed it.
Jun 3, 2020 at 8:30 PM
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KIWASABI1
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Just realized my manual says 15 ounces of refrigerant. Somewhere online said 21 ounces for my car. It wasn't totally empty, and I probably put in 3/4 of the bottle. So I'm going to have to bleed some out.
Jun 3, 2020 at 8:41 PM
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KIWASABI1
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I just did a quick search through the repair manual for PSI and found this that I've screen shot. If I'm reading this correctly, the low side pressure should only be 22-26 PSI when it's 95 degrees outside. When I first put the gauge on, it was reading about 34 PSI or so. I figured, that's on the low side of the green area (30-50), plus when it's hot you're supposed to adjust more like 45-55 I read. I really wish I just left it alone now. Gonna bring it to my mechanic I guess. Otherwise I'm literally bleeding out R-134A onto a towel, which is illegal I've heard.
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Jun 3, 2020 at 11:51 PM
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ASEMASTER6371
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Okay, the low side is not dependent on the temperature at all. When running, it should be 25-30 only. If it is higher, the expansion valve is allowing too much Freon into the evaporator.

The gauge you are using has those readings only for adding Freon. They are not indicators for the level at all. Do not think that the reading tells you anything but that you have pressure on the low side.

Roy
Jun 4, 2020 at 3:31 AM
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KIWASABI1
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Is there any way I can safely release the excess refrigerant until the car stops short cycling?
Jun 4, 2020 at 3:42 AM
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ASEMASTER6371
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No, you need a recovery machine to remove all the Freon, vacuum the system down for about 45 minutes and charge the exact amount of Freon required.

Roy
Jun 4, 2020 at 3:50 AM
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KIWASABI1
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We vacuumed it out down to 25 PSI. Now the compressor stays on. Perhaps not as cold as I'd like, but it's working. And as I posted above, the absolute MAX the repair manual calls for is 28 PSI when it's 105 degrees out. Erring on the side of caution with refrigerant from now on. Thanks for the help.
Jun 4, 2020 at 4:12 PM
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ASEMASTER6371
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You are welcome.

Always glad to help.

Roy
Jun 4, 2020 at 4:15 PM
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KIWASABI1
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This was not blowing cold enough at all on a 90 degree while idling. After hooking my lower side gauge up again, for me it was showing 30 PSI. I ended up increasing it to 37-38 and now it's blowing quite cold. From this Third Gen Eclipse specific site it says 25-40 PSI for low side pressure. 25-30 Definitely did not cut it on my vehicle. And I believe it was at 33-34 when I first started messing with it. At the end of the day it has mostly fresh R-134A in there at least, although it sounds like that stuff doesn't really wear out like other auto fluids.

https://www.club3g.com/threads/how-to-service-your-a-c-system-not-dialup-friendly.93372/
Jun 6, 2020 at 1:30 AM
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KIWASABI1
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Turned out it was actually at 30 PSI, but this was not blowing cold enough at all on a 90 degree day. So I increased it to 37 or 38 PSI and it's blowing good and cold now. This Eclipse specific site said 25-40 PSI was an acceptable range. While we're talking about A/C, are there any scheduled maintenance items I should consider replacing on my A/C to get it closer to working like it's brand new? It works pretty good now, but not like a brand new car or anything. And I don't want to top off the R-134A off any more.



Jun 6, 2020 at 1:33 AM
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ASEMASTER6371
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Yes, you will need to talk with Ken.

Roy
Jun 6, 2020 at 3:45 AM
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KIWASABI1
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I boosted it up to 37 or 38 PSI. A guide for specifically my car said 25 to 40 is acceptable. 25 to 30 was blowing way too warm when idling. It's much better now at 37-38 now. 34 was where it was before I messed with it, so 38 isnt much higher. The compressor stays running still, so doesnt seem overcharged. Are there any scheduled maintenance A/C items I should try replacing to get it colder? Or is a 20 year old car never going to compete with a brand new car A/C? I don't have a thermometer to test but it is blowing pretty cold honestly.
Jun 6, 2020 at 3:50 AM
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ASEMASTER6371
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How did you boost it up?

The lower the low side, the colder the air will come out.

Roy
Jun 6, 2020 at 4:10 AM
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KIWASABI1
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It was 25 or 30 PSI on low side and was very warm at idle. I used the recharge kit to go back up to 37-38 PSI. Now it blows much colder. When I overcharged it, it was even colder. But obviously the compressor was short cycling which was very bad. Up to 40 PSI seems to be acceptable for the low side on my car. At 38 the compressor doesn't shut off on its own anymore.
Jun 6, 2020 at 4:16 AM
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ASEMASTER6371
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Okay, but you overcharged it and that is not correct.

Did you use a charging machine to do the original charge?

Roy
Jun 6, 2020 at 4:19 AM
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KIWASABI1
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So what's the name of the sensor in these pictures that had broken loose? We soldered it back together and that fixed the A/C. It stopped blowing cold yesterday, and it has broken loose again. I don't think there's enough wire left on the sensor itself to solder it back together again. So probably gonna need a replacement.
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Jun 9, 2020 at 1:58 PM
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KIWASABI1
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I've circled the sensor in yellow on the diagram. Of course nowhere in the repair manual do they actually put the name of it that I can find.
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Jun 9, 2020 at 2:18 PM
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ASEMASTER6371
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The connector you circled is for the temperature switch.

Roy
Jun 9, 2020 at 2:27 PM
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KIWASABI1
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Can you find the part for me? Temperature switch just seemed to bring up the ECT sensor and engine cooling fan sensor. Which temperature switch are you referring to?
Jun 9, 2020 at 3:10 PM
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ASEMASTER6371
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Okay, I attached the part number for you. You need to contact the dealer parts department to confirm price and availability.

Roy
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Jun 9, 2020 at 3:20 PM
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KIWASABI1
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The part you linked appears to connect to the opposite side of the compressor from the connector I'm talking about. I'm attaching more pictures. It is a one wire connector that is housed in a ribbed gray plastic shell, and it continue all the way up to the main wiring harness behind the engine with the MAP sensor and such. So I suppose a complete replacement would include the wire all the way up to this point, or to replace the entire connector harness.
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Jun 9, 2020 at 5:07 PM
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KIWASABI1
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The connector is the round black circle connector in the bottom left of the last picture. It's right up next to the pulley.
Jun 9, 2020 at 5:09 PM
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ASEMASTER6371
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The only other connector is for the clutch itself which is part of the compressor.

I could not make out anything from your pictures.

Roy
Jun 10, 2020 at 1:21 AM
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KIWASABI1
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Mostly the last picture is the useful one. It shows exactly where the connector sits on the compressor. The black circle connector in the lower left is the connector in question.

Can you find the part number for the A/C clutch connector then? This appears to be spliced in directly to the main harness though. That's what the other pictures are supposed to show, that the gray sort of ribbed plastic housing for the wire continues all the way up to the main harness, splicing in right around the MAP sensor. There is no other connector that it plugs into, like the refrigerant switch sensor that you mentioned above does.
Jun 10, 2020 at 1:27 AM
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KIWASABI1
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Here's a perfect picture. It's the connector right by the clutch. So I guess you're right, it's the A/C Compressor Clutch Connector. I can't for the life of me find one online. I found Standard Motors part #S-1530 which is very similar, but it's 2-wire and has a slightly different connector from mine.
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Jun 10, 2020 at 1:47 AM
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KIWASABI1
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I finally found it in the repair manual. It's called Magnetic Clutch Connector in there. But searching for that brings up no results. This may simply be a junk yard item only.
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Jun 10, 2020 at 1:52 AM
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ASEMASTER6371
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There is no part number for the connector. It is not serviced separately.

You could just bypass the connector and solder and shrink wrap the wires together to eliminate the connector itself.

Roy
Jun 10, 2020 at 1:55 AM