AC System 101 Diagnosis & Repairing

[@27needles1]

Aircon Systems had always confused me. But your straight to the point education on 'Understanding the System' was awesome! Not even more than 5 minutes to explain how it all runs. Thanks and cheers!

[@PeterC3400]

After seeing several KZbin videos about Honda A/C diagnosis (and all seemed to point to a bad compressor), I borrowed an A/C gauge set from a friend. I was at 35psi low side / 150psi high side. Whew. Just low... One $12, 12-oz can of R134a got me into the 40s low side / 225 high side (idle, 95F outside). My 2007 Honda CR-V A/C hasn't worked this well in years! Freezin' my butt off now! Thanks for your tutorial! It helped me understand enough to fix it myself this time!

[@multidimensionalexploratio3985]

Great video guys! As I learn about my car's ac system, this sort of info is like gold! Thanks

[@johncasor9698]

the best explanation of how this system works so far i have found on internet... Thx so much...

[@gokhaleatul]

Your explanation regarding the diagnosis via guage reading was very simple to understand, to the point and very exciting, though component wise faults, diagnosed via gauge readings would have been very helpful... Really look forward for a complete video component wise.... Best regards

[@timmitchell4633]

First off, love the channel, and your easy to understand repairs and methods. THANK YOU AND KEEP THEM COMING. My 2002 Merc Benz S430 (W220) A/C stopped working after I replaced the windshield wiper hose (with the heater wire/ cable inside). The unit small red light is on indicating the system works, but will not blow cold air. The clutch does engage, on then off, constantly. The typical reset feature/ trick doesn't work for whatever this error is currently. I checked the relays/ switched and replaced them as well. Assuming the system may have been low on refrigerant, I filled it with what it took in, which appeared to be almost two full "tall" cans of AC Pro. Reset the system and the air came on "absolutely freezing cold" for about two minutes then shut off again. After resetting and attempting to make it stay on, it wouldn't reset anymore after four attempts. I noticed a clear liquid had leaked from the bottom center of the car down the driveway to the rear of the car, no smell or color, but thicker than water. The next day, with the engine running and the air refilled and reset once more, I heard a loud hissing and bursting flow of air or spray from under the hood, front drivers side for about 40 seconds then stopped. I believe it was a pressure relief vale of some sort !!! Scared the &%$#@^& %$#%^&%#@ out of me to be exact. The clutch still engages, on then off, constantly. Whats wrong with the cars AC ????? What would you recommend I check or replace???? No AC for the past four months now...

[@shmeehoe37]

You got to love how the compressor is right on top. I wish I had that luck LOL

[@bcampbell4880]

Ford made sure I was effed in that regard...

[@johndumas4467]

Howdy... love your vids. If I let all the r134a out of my system and vac it out, will I need to replace the oil. I'm handicapped and trying not to have to pull the compressor to dump the oil and refill. Thank you for your time. Johnny

[@senshilaserion]

Very informative. I've been experiencing AC issues for quite some time and this year I did three things. 1. R & R the AC compressor (old new was making noise) 2. R & R the condenser unit which came with a new dryer I then had the system recharged by a certified mechanic. Everything seem OK until I drove off 3 miles. The AC air in the cabin started to go to ambient temperature. Essentially AC system was cycling (compressor was turning-on-and-off) and the air did not get colder specially when the ambient local temperature got higher then 85 degrees. Then after watching some videos, I decided to replace the expansion block (valve). I had the system recharged once again. This time, the AC was blowing nice and cold, but then when I got on the freeway the air in the cabin started to get to ambient temperature. So, am scratching my head on this one because everything checks out (no leaks and the system the adequate amount of gas and oil). Any thoughts are welcome as this AC quest continues. Thanks

[@jeremymtz360]

If everything is working fine it could be something small....Ac control knob on your dash or even the blend door actuator car has one....Its what opens n closes to let air thru for heat or cold its usually in the glove box area. Hope you figured it out I got 2 vehicles Im trying to DIY myself

[@kreepingdeth198]

Might have a blockage in the system, debri will quickly clog the new parts

[@territodude]

Thank you, excellent video!

[@ChandraSQLVideos]

Good technical info..Helpful how the AC system actually works with your model AC..

[@zofa300]

Thank you. great video. If i want to connect the hoses to the high and low side, do i need to purge the hoses or no need as I just need t get some readings. No intention for charging. thank you

[@jamesolasunkanmi5360]

Very good technical. I love you. I learned a lot of things

[@AltonRowell-gb1lb]

Replacement of the condenser is allso required. Any time a compressor failure happens u have trash going to the condenser. No amount of flushing will get it out. Be careful of what u here on these videos. These people are selling parts not satisfied customers. I been mechanic for 40 years.

[@AltonRowell-gb1lb]

There selling parts.

[@kenswitzer4133]

Great video. Mark on! Gauges are affordable for most people. Amazon has them from 40 bucks up. Guys like you can provide advice on which ones add the best bang for the buck. 👍👍👍👍👍💥✌️🙏🏻

[@Swenser]

My standibg pressure is 120 psi. Compressor clutch works and compressor seems to try to do its job. But low side drops by a few psi and vibrates very noticeably. High side stays at 120 and vibrates but not as much. Im thinkibg blockage rather than bad compressor. Perhaps expansion valve? What do you think?

[@anthonysmith5979]

I have this job tomorrow, very little difference in readings when the clutch pull in, I added a bit of refrigerant just to see and it didn't make any difference so i've got a new comp' to install, i'm just hoping it's not the tx valve that opened and faulty, I have one just in case but won't be fitting unless i have to. either way it will be fixed. licenced here in Australia.

[@taufiqhidayat1707]

I want to ask about my car's AC problem. The air conditioner is not cold anymore when the car is at a speed of 50km/hour. below the speed, the AC is still cold. I tried to test up to 4000rpm for the N and P car positions, the AC condition is still cold. I tried the compressor, the compressor sound a little rough. what do you think the problem is? Thank you in advance. my car uses a clutchless compressor (using a solenoid)

[@ppptjohn6948]

if low pressure around 30 and high pressure around 250 while in max cold and max air blow. it is consider normal or overcharged?

[@QLFProductions]

I need guidance from any HVAC tech please. I replaced the expansion valve and the filter drier. With the engine not running the gauges read 60/60. Once I run the engine and turn the AC on the compressor clutch runs and the condenser fan spins but the low side goes into a vacuum and the high side goes to 80. The expansion valve turns to a block of ice.

[@UmarFarooq0300]

My Hilux Truck Low side pressure is 50psi & High Side is 300psi so the Compressor is good or bad?

[@blueoceanengineering]

Expantion valve likes valve can throttle if Clogged?

[@papabits5721]

What’s a compreshure

[@jamesregan5438]

I think it has something to do with the conpensator 😂

[@daveyboy8907]

Or maybe the carbatrader

[@louisvillalba7695]

😂😂😂😂😂😂

[@666miguel99]

My 2013 VW Jetta takes a very long time to blow cold. What could be the problem?

[@N.E.ACMG47]

Many thanks for the education!!!

[@zeke112964]

@ 4:42 it states in 1966, R-12 was banned due to damage to the ozone layer.....I don't even think they were concerned with ozone in 1966

[@heyitschinoable]

zeke112964 1996

[@juanrodriguez-ry6yt]

@@heyitschinoable 134A CAME OUT 93

[@heyitschinoable]

juan rodriguez you’re right . It became standard in 1994 forward

[@cognac8297]

It killed people when leaking inside your car. These people don't know history just peoples theory but soros was around then also and change words and meaning freely

[@joseurbina2474]

Very good and great video is helpfully . Muy Kia Sportage 2016 a/c is not working. I try to put Freon when I did the needle on the gauge when all way to red side . Until now I don’t knows is compresor need to replace it or maybe is a electrical problem. Can you give some tips to find out how fix my car . Thanks for you help .

[@MiamiWebDesign]

What if the low is too high and the high side is too at the same time? My truck is at 70psi on the low and 145psi on the high at 95 degree weather.

[@sandcrab911]

When receiving a new compressor do u need to add oil to it or will the machine add it with the freon?

[@kkampy4052]

drain the oil out of the old compressor, measure it and add the same amount to the new compressor.

[@yukselcelep2827]

Hello there What is the failure of the expansion valve can cause the system. affair is doing hose icing ma from compressor valve. Thanks

[@phillippardo5712]

Could a pressure switch or expansion valve cause this?

[@jean-francoiscaron1945]

what can cause a high pressure reeding low if the compressor is new?

[@asifznz]

Very very good explanation

[@yabasvlog3439]

Great job

[@eddymartinez1574]

What if the low side reads normal but the high side reads low what could the problem in my case?

[@Devo1987]

Hi my 2006 mazda 3s 2.3L A/C stops blowing cold after idle slow driving a/c works when im moving traffic fast car doesn't overheat / fans run / ac pressures good / new condenser / new dryer / new a/c clutch / New fans would you know what is my problem is ?

[@davidsmalling3278]

Great video but just one question. My toyota corolla 2008 AC blow cold air then warm air. It does this repeatedly. What is the cause of this?

[@jimmynorth557]

Bad low side pressure switch

[@RoxerBasho]

what gauges are being used?

[@sotheamam1244]

Hi..John, I'm replacing a new ac compressor. Do you know if the new compressor need oil? How would I check that. Can you possibly do a video on how to change a new ac compressor from start to finish. How to check for oil or add oil..

[@carolynsummerford6653]

See@Ken Say

[@carolynsummerford6653]

Ken a mechanic tried to add fefrigentbti my AC my compressor was fine I've never heard it even run especially inside my 2013 Ford eco boost truck and he said he needed a paper clip he put that in a place inn my AC compressor and it wouldn't shut off even after my truck key was turned off he removed my relay to try it in his wrecker which is a 2005 Ford f150 deisel why did he do that and now it runs while I'm driving and doesn't shut off for fifteen seconds afte. It's tuned off

[@coycarlson4979]

Replace the compressor ? I guess you checked that the compressor clutch had power when you switched on the A/C and that the clutch was pulling in to engage and therefore turn / spin the compressor ? VIA the serpentine drive belt. Any technician knows that your compressor will not pump refrigerant if the clutch doesn’t pull in and engage the compressor to the engine.

[@PANTYEATR1]

95 Mustang, my low side is maxed out on the gauge, the high side is at zero. Compressor clutch is disengaged. What's the problem? Thanks

[@braddahjon9617]

i have subscribed and liked

[@aguitarhero007]

When I hook up the gauges I have 47 on both the high and low side. When I turn the AC on neither the high or low side move at all. They stay the same at 47. Also, the compressor clutch engages when I push the button. I can physically see it spinning. Does it sound like I have a bad compressor?

[@dunebashing3884]

Yes

[@johnkapel2128]

Duh.....I think so

[@cognac8297]

@6:43 he just said that man he answered the question to. That's why your ac don't work you don't listen

[@toupsclassroomtoupsclassro9557]

Question: rv high pressure side is sweating and not blowing cold any ideas?

[@johndoe2022]

HI, MY AC stopped cooling. My high and low gauges shows 125 psi when car is off. when I turn the AC on, the high gauge still shows 125 psi, buy low side drop to10 psi and stay static there. the clutch seems good. what is the problem? thank you !

[@AltonRowell-gb1lb]

U have a blocked system. U should feal a cold place where the blockage is. Use you hands or a lazor thermometer to find it.

[@AltonRowell-gb1lb]

It could be a stopped up line or a condenser problem. After u find and repair it flush out the system and replace the filter dryer and add the proper oil type and amount. Then vacuum it for 30min. Put the recommended freon weight in and recheck it.

[@johndoe2022]

@@AltonRowell-gb1lb Thank you! Where is the filter dryer located?

[@aldrickmoore6908]

Tech guys I have a question for you...my ac compressor is cycling on and off but still blows hot air, I replaced the liquid line it gets very cold but the accumulator is hot , checked for leaks and change the low pressure valve but air in the car is blowing hot air.

[@heyitschinoable]

Seems like you have a restriction/blockage. Your liquid line, which is on the high side should not feel cold at all. Accumulator should be cold and not hot. Run your hands on your ac lines if any ac line feels hot then suddenly cold or accompanied by frost you have found the restriction.

[@joeshmoe781]

The refrigerant DOES NOT HEAT UP. As the refrigerant is pressurized the heat is pushed out of it. That is the job of the condenser, it diffuses the heat. W/o the heat being able to be extracted from the system the gas would not turn to a liquid. That is why on very hot days or not enough air blowing thru the heat fins of the condenser the system can't compress the gas and it is no longer able to cool. Furthermore, when the liquid expands and is able to form a gas it absorbs heat. That is the job of the evaporator, the warm air blows over the heat fins and loses it's heat to the gas. and Repeat.

[@thincrediblewho]

At the end of your explanation, you say that the refrigerant absorbs the heat... So it does heat up. It's not entirely accurate to say that the compressor heats the gas... Which is what I think you meant. Technically, it's the same amount of heat, just compressed into a smaller space. However, it FEELS hotter because the heat is concentrated. Then the heat is dissipated into the fins of the evaporator, the cooler freon expands, with FEELS colder because it can absorb more heat than the surrounding air (or the higher pressure cooled freon).

[@peterbuiltcummins413]

"Compressure"

[@CORZER0]

Stop saying compressure

[@saavedrajoseph5635]

@@CORZER0 \\

[@johnhernandez8539]

Hello guys interesting I have a 2014 Elantra air con is not working properly it's cold at times and hot after and do not get back cold.The gas is good I took the car to a repair shop and was told that the a/c thermostat is bad I don't trust these shops here can you give me advice on this problem from your knowledge weather its the thermostat or not.John HernandezFrom Trinidad and Tobago Caribbean.Thanks

[@thincrediblewho]

If the shop is trying to make money by lying about the cause, it's unlikely they'd tell you it was the thermostat. That's not part of the sealed system, so it's one of the easiest parts to replace. That means low repair bill. If they were trying to scam you, they'd tell you it was the compressor. If you think they're just incompetent, I'm not sure what to tell you. I'm not knowledgeable enough to tell you what the cause is. I'd replace the thermostat and see if it works, but for me that would only cost me the price of the part.

[@georgeolt654]

Very educative!

[@kenholt8297]

very educative?😮😂😂. You mean "educational"...

[@georgeolt654]

@@kenholt8297 They are similar words. Please, gogle it! Next time, festina lente!

[@deepcheema9086]

How to know its air inside ac system not refrigerant with manifold guage

[@cbarkwell1000]

You'll have to use a Rêfrigerant Identifier to obtain both of those important ănswers. kzbin.info/www/bejne/i5ecmnt3jdCIl6c

[@smalanning9693]

👌👍

[@jimsamois8502]

You stated the refrigerant left the condenser as high pressure liquid and went to the reciever dryer which is NOT true. The high side of the system is NOT connected to the reciever dryer it comes out of the condenser and goes to the metering device. The reciever dryer is connected to the low side after the evaporator I've never seen a system like you've described

[@cbarkwell1000]

High Side Line of Compressor to Condênser to RECEVIER DRỶER to EXPANSION VALVE to Evaporator to Low Side Fitting of Compressor. The othẻr Installation : High Side Line of Compressor to Condênser to ORIFICE EXPANSION TUBE to Evaporator to ACCUMULATOR to Low Side Compressor Fitting.

[@pctuterman1]

I think they made a typo on the date that R-12 refrigerant was banned in the US. I should have been 1996 as opposed to 1966.

[@joeshmoe781]

@MrDusterdave Some cars in 95 came with r-12.

[@jimhill6586]

All cars were converted to 134A in 1996. What R-12 that remained on the shelf, bought up by those that knew it was done. I bought and used R-12 for years. Had some until a few years back for old legacy AC.

[@pctuterman1]

​@@jimhill6586I think I have a hole tank full.

[@heatncool]

Can you use a 7 cfm vaccum pump on auto ac or do you need a 2 cfm?

[@aaronmcdonald4944]

From what I heard, a 1.5cfm and up is okay. I'm about to order the Zeny 3.5cfm. should be enough, and its affordable

[@johnsouthland3225]

Vac is vac (as in, you can't get MORE than a total vac!). The CFM (higher or lower) is just how fast (or slow) you'll eventually get there. Think of it like emptying a swimming pool with a drill powered pump attached to a garden hose or a fire pumper truck.

[@heatncool]

@@johnsouthland3225 thanks. I was just wondering perhaps its too powerful and could damage the compressor and or the metering device, filter etc by higher then neccesary suction pressure. Thanks for the input.

[@reynanfernando6079]

Why my high pressure don't go up, maintain at 100psi

[@justy8903]

I have Nissan Altima SV 2013 model , I have AC problems since 3 years , Since then, every year I go to various Car AC mechanics , No one able to fix it so far only emptying my pockets each time, They did everything , but nothing works . Last year One mechanic says it must be problem of compressor , So I changed into new compressor as per his suggestion , but still not working every time it blows hot air, I fed up of this problem , Moreover too hot summer , here in New york city , where you live Could you please help me what exactly is the problem in AC

[@diygaragebryangregorytv9834]

That’s rough! Your next and most important step is to have the entire system checked for leaks. Sounds like a leak issue in which case a new compressor, condenser, evaporator/drier, etc will not solve the problem. If refrigerant isn’t present you won’t have any cooking capacity. Good luck

[@AltonRowell-gb1lb]

So you replace a compressor without flushing the system. You need to replace the condenser allso guys. And flush out the evaporator with a flushing mechine.

[@charlievanwindt7145]

They don't need to replace the condenser, there is nothing wrong with the condenser. The car has a bad compressor, so they need to replace the compressor, if the filter dryer is very old, it would be wise to replace that as well while working on the system. All that's left to do is to pump the ac system down to about 20 Microns (almost a perfect vacuum), then check for leaks (if the system does not hold the vacuum), and recharge it, that's it.

[@joe-gd3pg]

enough with the ac compressor hows about videos diagnostics on expansion valves high and low pressure switches and the driers

[@tedenderpal1299]

I was quoted $250 by two different AC shops to recover Freon then evacuate and refill the system.

[@yashpalsinhzala4345]

Thanks sir

[@melvinhernandez5074]

What happened with. The rest of it??

[@kevinferrell1739]

2000 Jeep Cherokee... Will not Take Freon... Compressor worked great in the other jeep. I start the car turn on A/C controls, Hi/max, When I unplug the ac compressor i still have power on the compressor end/plug but no power on the plug wire coming from the wiring harness. Only time that wire has power is when the ac is plugged in. Is that right?? My low pressure switch 4 ports has power on 3 out of 4 ports/slots. My high pressure switch 2 ports has power on both ports..{update } car running ac controls on, if i unplug my low side sensor i then have a hot and ground on the high side switch instead of 2 hots but low side switch has 3 hot 1 neg. unplugged... i did test the wire thats going into that port and it has power going in the switch but no power in the port of the switch. If i hook the low side back up, again i got 2 hot ports on the high pressure switch. Even when i have 1 hot side other neg or no power on the low side it still wont cycle the clutch and when i plug back in the low side sensor and try bridge the high side switch it then will blow the big 20 amp fuse. So could my low pressure switch/connector be bad if so will that keep it from accepting freon. Also my electric fan dont kick on even if i bridge the clutch over,,,

[@donworryboutit8455]

Its the compressure... 😂

[@vijayanvijay1361]

Hi sir gud evening in gauge psi is not stayable working up and down sir wht is problem sir

[@pktv9028]

Do you can give work permit, i from Bangladesh, i can do automobile

[@kenholt8297]

hmm... yeah, leave your watch on while you work...😮🎉😂😂🎉

[@cassielao8463]

mines drop down to 35 and the high goes up, but no cold air...

[@globalpioneer5076]

You are probably low on coolant , if there is no air flow at all , check see if you have a cabin filter,

[@fibes2746]

compressor isn't kicking on? Replace the compressor, ofc. Diagnosing 101 brought to you by Advance Auto Parts.

[@RobertoHernandez-jm1bf]

HOW CAN I GET MY LISENCE TO WORK WITH A.C.?

[@rhshel]

Mine takes Freon 12 so fix my van 86 GMC Vandura

[@axenz1]

That's it?

[@joefixxit]

New txv, New Air dryer, recharged system.... normal lowside LOW highside... no leaks compressor kicks in normally..

[@thegreatone358]

Link to PART 2 I'm not sure why this wasn't linked. kzbin.info/www/bejne/h4irnn2KqLyEaKs

[@KudirataduniSulaimon-dy1vf]

Hello please wanna learn how to repair and install car Ac

[@frankmolina2076]

Great video with the exception of the factoids constantly coming up and ruining.it.

[@rhshel]

compressor has a slow leak ?? call rock auto

[@AltonRowell-gb1lb]

I buy from rockauto to.

[@peternajduk7841]

Recover refrigerant. Evacuate air and moisture

[@Mentorcase]

Gee I wonder why they call it an evaporator, considering you claim it turns a high pressure liquid to a low pressure liquid, let me guess then the low pressure liquid goes back through the commressure!

[@yilancio]

I'm sorry, but I had to rewind 2x from 1:14 to 1:21. WHAT THE HECK IS A "COMPRESSHER"?!

[@AltonRowell-gb1lb]

That's when u compress her.

[@Carlosalberto-bg4ot]

LOL

[@melvinhernandez5074]

Make a full. Video not a comercial. Something educational waw

[@baskorobas7550]

Apa nama mesin itu, apa funsingnya ??

[@haouesmessaoud4088]

I am looking for a job with a certificate in car air conditioning repair from Algeria

[@bjhachannel6747]

no body buy or have big a/c system test like you bro i think you can used basics a/c system gauge test better used big and expensive one peoples they do not have expensive tools like you do bro

[@jkohutiak]

great video but i have a hard time hearing you even on 100%

[@rafeeqfitness5998]

Wounderfull video

[@MikeSmith-nu9wt]

Now when they made me go back to school on ac , cause r12 switched too 134a , they said 134a wasn't bad for the environment like r12 was , so we can let it blow off in the air , can't we ? Lol ..jk Now they wanta switch again , now we figured out why ..I rarely use freon anymore in my ac ..

[@rhshel]

yea everyone has one of thos costly machines??? give me a brake. Freon 12 is costly why dispose of it

[@thincrediblewho]

If you need a break, or a brake, you're the one who needs to supply it. Nobody here has done anything to earn your ignorant criticism. No, not everyone has one of those machines. If you were listening to the video, they told you "this is where you're gonna need to take it to a shop..." Etc. I'm not sure about Freon 12, but 134a (every modern car uses 134a) is illegal to release into the atmosphere. You HAVE to get it evacuated by a professional, because only a professional who does it for a living is going to have the certifications to handle the stuff and the equipment to do it. Why dispose of it? Well, I don't know if it's ever reusable, but if you're removing any competent from the sealed system, you can't just keep it in. It still has to be evacuated, or it escapes into atmosphere. Personally, I wouldn't reuse freon (assuming it's possible) because I don't know how much water, air, sediments, and lubricant are in it. If I'm gonna go to the effort and expense of fixing my AC, I'm sure not gonna put the new components at risk of early failure because I was too cheap to put in new gas. AC work is expensive. You can't escape the evacuation requirement, without facing major fines and severely hurting the environment. This video is helpful because it teaches you some diagnostics, and how to do the part-changing work yourself. If it saves you half of the cost of having a professional do the whole thing, it's saved you hundreds (maybe over a thousand) of dollars.

[@emmettthompson3332]

I know what's worse. A red hot poker in the eye. Not much worse than that.

[@fatdan3122]

It's not just this one but, why do all these videos need an intro? It's a waist of time. Just get to the point.

[@noluv420]

Can't take a mechanic who wears a watch seriously

[@Mikefngarage]

SO funny Takes a AC Certified technician to hook up 2 lines and push a button....... What a country we live in. In some other countries they just let the freon into the air.......Lets vote in more of the democrats so we cant do anything ourselves.....OMG really and have more certified button pushers.

[@kennethvenegas8187]

Q mierda en ingles

[@CHIBA280CRV]

Wow ! to say you need a compressor, just cause the gauges are not moving is Crazy ! How about a fuse , or a clutch , or how about a shorted line ? This video is misleading!! If someone is looking for answers on there vehicle ac system and they run out and replace the compressor and it still doesn’t work , shame on this misleading video.. and you guys that made this video..unbelievable...

[@AltonRowell-gb1lb]

Teach your mouther to suck eggs. I been doing this before u were born.

[@jameylane9196]

Don't listen to these clowns.

[@bobbyk6585]

Trying too hard to be edgy. Lose the intro music and "cool image" flashes. Stick to providing accurate information and you'll get the views/thumbs-up.

[@Rico702Vegas]

What is a "compresher"?? English bro, the only language you know..