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Fucknag posted:Yeah, clutches don't really seize at all, they either short and stay on all the time or wear out and don't engage. It's not so much the clutch seizing as it is the bearings that let the pulley freewheel. When those seize up (especially when you've got a locked compressor) the whole thing is going to act like the clutch is seized, whether or not it actually is. True story, the load of a locked up A/C compressor is enough to make a '95 Saturn SL1 not start.
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May 12, 2014 23:56
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If the compressor isn't kicking on at all, then you aren't seeing a running pressure, you're seeing a static pressure. There should be a relay to control the compressor, and a fuse associated with it - look in your owner's manual to figure out which is which. There's also the possibility that the coil on the compressor has an open circuit, which you can typically diagnose with a multimeter by checking the resistance across the terminals on the compressor itself.
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Jun 3, 2014 17:11
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I'd do what Motronic said first, honestly. A 2010 is too new to have normal refrigerant loss cause the compressor to not cycle on, so if the static pressure is low enough that it's where the running low-side pressure is, it's most likely a leak somewhere.
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Jun 3, 2014 18:28
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Absolutely, insufficient airflow can and does lead to icing. Same thing happened to my mom once after my parents divorced (less all of the new hardware); my dad had installed cleanable filters and she had never cleaned them. Eventually one of them clogged enough that the evaporator iced up. Badly enough that if you walked on the concrete next to the air handler where the refrigerant lines run through, the concrete was cold
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Jun 8, 2014 04:35
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Step one is going to be stop messing around with an all in one can and get a set of gauges on it. Hook up a vacuum pump and see how it holds from there.
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Jul 5, 2014 01:21
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FogHelmut posted:2002 Ford Taurus It's a mechanic who doesn't know what he's doing, so it's a good thing he declined. In a Ford like this (my Ranger does this too), yes, the ECM is technically controlling the A/C - but it's not actually using any special logic. There's still a pressure switch (or two? I don't recall), the only difference is that it feeds the ECM instead of directly wired in series with the compressor coil. The ONLY thing different about this, is that the computer has the ability to cut the compressor off at WOT. That's it. Otherwise it cycles in the exact same manner as any other A/C, and there's certainly no 'calibration' needed. This is a 12-year-old Ford we're talking about, not a 12-year-old Mercedes or anything modern with some crazy ability to vary cooling loads. The compressor is either fully on or fully off, and is only commanded by the same pressure / temperature switches you'd see on any other car. So, basically, ignore the fuckwit mechanic and go to the third post and start going down the list from there.
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Jul 15, 2014 16:51
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There's a lot more that could be going on. On my Ranger I actually had an intermittent open circuit in the compressor coil - it started off acting like it was undercharged and would even test good on a resistance check. Couldn't diagnose it properly until it was failing more often than not. But yes, if the pressures all check out, then time to check the pressure switches / relays / coil. In my Ranger's case the A/C relay is just another part of the fuseblock, not in a separate CCRM.
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Jul 15, 2014 17:11
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The other possibility is that its just normal noise or not even directly related to the A/C. My old NB Miata would rattle like that when in neutral with the clutch out and A/C on. Pushing the clutch pedal or turning off the A/C would quiet it down. As far as I know, the A/C is still working cold and that noise was there since 2004.
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Mar 14, 2015 19:54
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The throwout bearing did eventually poo poo itself and take the clutch out with it... but that was somewhere around 2012-2013 I think, and 80,000 miles after I first noticed said noise. It was about due for a clutch by then anyway. I haven't actually been in the car since it got the clutch done. My mother in law still owns it, I just have zero reason to ride as her passenger 
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Mar 15, 2015 18:24
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My wife's CRV will freeze you out even in the middle of June, though (like every other car I've ever owned here in AZ) it will take some time to get there. You're comfortable fairly quickly.
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Jun 15, 2015 03:29
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Motronic posted:If you don't have a recovery pump and dedicated tank for it you're pretty much on your own. I'll leave it at that. I love how the second you put it into an A/C system, you aren't allowed to do what it was sold to do - vent it to atmosphere.
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Jul 6, 2015 14:48
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Okay, now I'm confused. 2003 Jeep Grand Cherokee, V8. A/C wokred great earlier this week. When I fired it up this morning, no A/C at all. On the drive back home at the end of the day, it worked again for about four miles. Rented a gauge set from Autozone, static pressures are in the 115-120 range both high and low. Can't get the compressor to kick on. Couldn't find my can of R134a but it shouldn't matter, the low pressure switch only needs about 30-40 to engage so that shouldn't be the issue. Coil tests good (about 4.8-5 ohms) and there's at least 13V at the connector when I disconnect it and check it engine running. Compressor isn't seized, I can spin it by hand. I'm thinking next step is taking the clutch off and see what lies beneath?
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Oct 9, 2015 07:43
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It's a two-wire coil, so it doesn't depend on a ground from the compressor itself to work - the 12V I got at the terminals was from one pin to the other. Might give that percussive maintenance a shot.
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Oct 9, 2015 14:32
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Yeah, I was spinning the center of it (engine was off, belt was stationary). It was also not noticeably warm, which I would've expected if the compressor had suddenly seized with the clutch trying to engage. Valid point on the voltage testing, but I don't see any way to probe it without hacking up the wiring more than I'm comfortable with at the moment. It ultimately just uses the PCM signal to switch a relay. I'll throw a jumper on that tonight and rule the relay out just to be sure.  SPP: I haven't tried that yet, I couldn't find any alligator clips in my garage and the connector on the drat thing is shrouded so deep I don't want to just try the "stick the pokey bit in until something happens" method. I should probably stop by Fry's or something tonight and build/buy some proper leads for this purpose.
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Oct 9, 2015 18:56
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Enourmo posted:You could also pull the relay and jump it using the ammeter, to check current flow through the clutch itself. Looks like it's constant ground, I was thinking a bad pressure switch but it looks like that's a separate input rather than inline with the clutch circuit. I like this idea a lot. And yeah, neither the high or low pressure switches are inline with the clutch - they're all just inputs to the computer, and the computer grounds the relay whenever it wants the compressor on. ShittyPostmakerPro posted:My compressor siezed while running and yes, the clutch got very warm (ended up stripping the friction material rather than slipping on the belt!). Spinning the centre (input shaft) should feel pretty smooth, maybe a bit lumpy depending on design. The pulley should, of course, spin freely with no belt installed. I once had to work on a Saturn SL1 where the compressor (and clutch) seized. You couldn't start the engine with the belt still routed around it. "Smooth but a bit lumpy" is exactly how it felt. Given the lack of noises I'm confident that the compressor guts are still fine. The only lovely thing is if I do end up needing a new clutch, they cost nearly as much as the whole loving compressor.
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Oct 9, 2015 20:20
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Enourmo posted:You could also pull the relay and jump it using the ammeter, to check current flow through the clutch itself. Yep, even though it shows low resistance to an ohmmeter (now about 7Ω instead of 4Ω), as soon as I set up a multimeter as a jumper it only passes 0.01A. I'm going to call the coil toast. How is it that I've had two separate vehicles burn coils in two years?  Just to piss me off more, it also puked a bit of coolant (the upper hose is already failing again) and my HF snap ring pliers are too small to get the snap ring off of the compressor. At least Autozone has the coil in stock and it's only $34 instead of $120+ for the whole clutch from Amazon or Rockauto.
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Oct 10, 2015 03:43
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Whoever wrote the Chrysler service manual for the WJ can eat an AIDS infested dick. There is no loving way a set of snap ring pliers big enough to get the job done is getting in a 4.7L compressor unless you either remove the compressor or the radiator / fan. Thankfully it isn't too bad to remove the compressor and there is juuuuust enough room to tilt it up so you can get a straight-enough shot. I also drat near crapped myself. I tested the clutch manually a dozen times before I popped the relay back in, and it clicked every time. After the relay went in, nothing. Just needed to reseat it since after doing so, it works great. Also, while I'm glad it was only $35 after tax for the new coil, I wish they'd put the right goddamn connector on it. I did get some good use out of my new stripper.
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Oct 10, 2015 08:40
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Got the system vacuuming right now after a compressor replacement. The instructions with the new compressor said to dump the oil from the old compressor, measure it, dump the oil from the new compressor, and then put the amount taken from the old compressor back in. The only thing weirding me out is I only got maybe 1/8 of a cup out of the old compressor, and at least 2-3x that out of the new one (a Denso new-build compressor). The old compressor itself was fine, I'm just replacing it because the clutch alone costs nearly as much. Do I need to dump some oil back into the system when I go to fill it, or is there really supposed to be that little oil in the compressor?
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Oct 18, 2015 03:33
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I just googled some more and yeah, it looks like the oil they fill it with is assuming a fully dry system. I guess I'm good with the relatively small amount that went back in.
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Oct 18, 2015 04:12
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Charged it, no unusual noises so I think I'm good. I did it by weight (27 oz, about the worst number for 12oz cans). It's humid as hell and my low side pressures / vent temps didn't get to where they should be, so I'm thinking I froze the evaporator over while charging. I'll give it a check in the morning.
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Oct 18, 2015 07:34
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Only vaguely related to all of that - how the hell is it that my CR-V, which takes a full charge at only about 14oz of R134a, consistently kicks the poo poo out of my WJ in terms of A/C performance? The CR-V's A/C is one of the best I've ever seen here in an AZ summer.
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Oct 20, 2015 23:44
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Goddamnit. Discharge line on the Jeep started leaking just below the crimp. Must not have liked all of the bending from the compressor and receiver/dryer replacement.
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Oct 24, 2015 21:38
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Double posting because I don't know what the gently caress. Replaced compressor, receiver dryer, and discharge line. Vacuumed, no leaks, recharged, and worked great for maybe 30-40 minutes. After another 30-40 minutes I got less and less cold air, no reduction in airflow. By the time I hooked up the gauges I was getting basically no cold air at all. Compressor never cycled off as far as I can tell. Nearly 90 degrees out, here's the running pressures.  Maybe too much oil in the system?
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Oct 25, 2015 21:27
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You'd think so but it doesn't. Turns out later WJs omit the low pressure switch. They monitor the actual pressure of the high side with a transducer, and the temperature of the evaporator coil.
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Oct 26, 2015 05:17
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Dealer option, not present on mine (yet). There's no bypass around the evaporator and I didn't get any reduction in airflow so I really don't think it froze. I could always pull the glovebox and check - I hacked a hole in the side of the HVAC box to replace the blend doors last year.
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Oct 26, 2015 05:58
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Yep, never cycled off. Might fire it up a bit tonight or more likely tomorrow to see what's up.
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Oct 26, 2015 06:44
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You're talking about the same genius HVAC engineers that decided watching for a massive current spike in the blend / recirculate door actuator motors was better than installing some form of actual position feedback. The motors themselves are strong, and the plastic stop pin is extremely weak, so they quickly break and rely on the doors themselves. It's got to be very close to a 100% failure rate.
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Oct 26, 2015 17:17
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Motronic posted:lolgmnolowpressurecutoff More like lolmoparfactoryzipties I've got a partial can left, I'll weigh it tomorrow and throw it in and see how much I add / what (if anything) changes on the gauges. I did drive it tonight on an errand - 10 minutes out, 10 minutes parked, 10 minutes back. Vent temps down to 40 degrees (80deg ambient), started warming up to maybe 45 degrees as I pulled back into the driveway. \/\/ If I can duplicate the zero-cooling situation again at home, I'll see if I can shove my inspection camera far enough down the center vents to see the evap. IOwnCalculus fucked around with this message at 06:13 on Oct 27, 2015 |
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Oct 27, 2015 06:09
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mafoose posted:Have you tried a static pressure reading after it sits over night? Won't that tell you if it's under charged? Pretty much what Enourmo said, but for shits and grins:  79 degrees ambient, by the way. Running pressures tonight - didn't add any since I didn't have enough time to do so (and didn't want to gently caress around with it any more than necessary without gloves - need to buy more)  Again, 40 degree vent temps for a short drive, won't be until Thursday that I take it for a longer one. However, I did notice something interesting that is making me start thinking yeah, it is slowly leaking. When I popped the low valve off, the schrader valve stuck open a bit until I poked it with a screwdriver and got it to reseat. I'm wondering if the low side valve is leaking, and in that case, I can't decide if I either want to buy the tool to replace it without having to recharge it (again) or if I should just replace the whole hose (which would take about five minutes once the system is empty).
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Oct 28, 2015 07:01
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 Yeah, at this point, step one is to see if I can cram enough R134a in there to get those pressures in range. If I can, then I'm going to order one of those Mastercool valve tools and a replacement valve set. According to Amazon and Rockauto, this fits my Jeep. Now I can't decide if I'm good just getting the ~$35 Schrader-only Mastercool tool, or if I need this $75 set or this $140 set.. It's only money  If I can't get the pressures up, I'll plan on a TXV replacement and just replace the whole drat hose (and the dryer, again, ugh).
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Oct 28, 2015 21:27
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Good to know, I didn't know if those other tools were anything you'd come across these days. I did throw another can in it (took for loving ever to do so, as well) but the low/high running pressures haven't budged at all. The air temperatures have dropped a bit, but the vehicle was heatsoaked and sitting there idling for the better part of an hour. At the same time, it didn't freeze up at all today - but I haven't taken it on a long highway-only drive yet. I'm about at the point where I'm just going to leave it be for the winter and deal with it next summer if it freezes up again then.
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Nov 1, 2015 02:36
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As lovely as it is, that sounds like the most logical answer to me. I've got UV dye in it, and a blacklight... somewhere, I just used the loving thing to confirm that the oil getting sprayed around the C10 is in fact the front main seal. If it's the evaporator - and knowing my luck it will be - the whole interior has to come out. I guess at least if that's the case I can replace the passenger side blend door motor and the recirculation door since both of them are in really sketchy shape and also require the dash out.
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Nov 2, 2015 19:23
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The dye is suspended in the oil, is it not? I think that's your answer right there.
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May 3, 2016 17:16
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I'm assuming that the compressor wasn't just rapidly switching on/off, correct? I'd be inclined to look at a HVAC control problem rather than a refrigerant problem - blend door / actuator failure or something along those lines.
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Jun 2, 2016 21:55
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The real risk there is why is the compressor intermittently engaging. If the clutch or clutch coil is the reason, then sure, replace those parts and don't gently caress with anything else. If it's intermittent because it's low on refrigerant, then you need to diagnose where the leak is, evacuate the system, replace whatever part is failed (plus a new drier), then reoil / recharge as needed.
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Jun 27, 2016 23:19
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You can get the tool from Autozone if you need it. On both my WJ and my Ranger I was able to get the job done without it, except for tightening it up on the Ranger.
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Jun 29, 2016 02:50
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Also, does the blower motor run on a relay-fed circuit at full speed? My C10's original wiring ran the blower full load through the fan speed switch, which surprise, leads to melty switches and connectors. It ran noticeably harder when I set it up with a relay instead, though I was lazy and removed any ability to slow it down in the process.
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Jul 6, 2016 21:06
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If that's directed at me - the airflow at speeds below full is so dismal that if I want it turned down, I'm turning it off anyway.
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Jul 6, 2016 21:17
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Dagen H posted:2001 Chrysler Sebring: A/C works fine. Shut car off and restart, and it throws heat. Repeat at random. When it works it works great, so it doesn't seem to be low on refrigerant. Any ideas? It's a Chrysler?  So it's not just blowing uncooled air, it's going full on into heater? It's got to be controls at some level - electrical or mechanical.
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Jul 20, 2016 15:29
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revmoo posted:Blend door. I was thinking this, but if it is a failure of the actual door like my WJ had, it seems like it should just fail in one spot and not switch between the two. So I'd lean towards the actuator or the controls for the door.
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Jul 21, 2016 00:36
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