How a Car AC System Works - For Beginners

[@Super-Human1]

Ive never completely understood anyone except for this guy. Guy you explain this stuff perfect. I really appreciate it i know a bunch but ive learned everything else from these videos. Keep it up!! Ill for sure send people to your videos my guy. 💯 the BEST!!!

[@mclayhenry]

Best basic description of AC system operation I've seen.

[@rpruneau68]

Good job on tutorial. One clarification to note: A system that uses a clutch-cycling orifice tube as a metering device vs TXV thermal expansion valve as drawn above; utilizes an accumulator/drier that is located on the low-side between the evaporator and compressor. It is used to catch excess refrigerant liquid and lubricant oil that leaves the evaporator. It will allow some oil to enter vapor stream to help lubricate the compressor. TXV metering device system has a receiver/drier located on HIGH SIDE between condenser and evaporator. CCOC orifice tube system has an accumulator/drier located on LOW SIDE (w/ LS cycling switch) between evaporator and compressor.

[@richardnichols6927]

Did you not watch the end of the video? At 8:41 he mentions this.

[@janepoynter8097]

My condenser, compressor and expansion valve are all being replaced right now, thank you for such a clear explanation on how the AC system works! Great video.

[@TheOrderOfTheNewWorld]

Maybe you should try a laser pointer to point engine parts out. That way you don't have to stick your hands in a tight area and the viewer can tell exactly where you're pointing. Thanks for the video.

[@bluewindgau4688]

u r right

[@TheTruth-ge7fj]

Is that, he is! right.

[@paulinavazquez6444]

He did great! Tell that to a teacher on the year 1950’s and he will tell you , “get out of my class!” Laser invented in the 1960’s

[@johngoold1218]

This is exactly what I wanted to learn tonight (2017). Great explanations and thankful this was here.

[@multidimensionalexploratio3985]

Great video! This actually clears up a lot of things I needed to know while repairing my own ac. Thanks a bunch!

[@martinchun1130]

Very nice explanation! I know the very basics of auto mechanics, nothing to advanced. So recently my condensor broke and I had no idea what that was! Your video helped explain what I am paying the mechanic to fix! Keep making more videos!

[@8gomerpyle22]

....too advanced...

[@yko4life]

Wow great explanation. Although this was specific for a car AC system, this explanation is also perfect for any basic AC system. Great Job.

[@a1cjw1347]

Changed the a/c compressor (filled oil up to correct levels), desiccant bag (04 Hyundai Santa Fe, receiver drier attached on the side of condenser), expansion valve, and all the o-rings pertaining to each component changed. Put a vacuum on it for ~45 mins, let it sit for another 45 mins with no indicated leaks, charged the system up utilizing the manifold gauges to "correct pressures", unhooked gauges, got in the car and the air was warm.... Plugged gauges back in, and it shows low pressure side almost pegged, and high pressure side hovering under 150psi (it was almost 90 degrees here). When recovering refrigerant, the high pressure side drains faster than the low, and will always be lower readings than the low side. Every once in a while, the air will feel "cool", but nowhere near what it should be. Condenser fan is working great, radiator fans working, compressor clutch is engaged, and a/c switch works. My guess would be the expansion valve, but I wanted to get a second opinion from you. I've watched and learned from your videos over the years, and they are the most informative. Please help! Thanks!

[@MrCuau12345]

Great video! There's is not so good explained videos in spanish. So you helped me to learn how an A/C works, thanks man!

[@cameronmills8453]

Well Done Video, really simple and well explained. I wish he would've mentioned a few other things that are part of the ac system like the high and low side pressure switches and the condensation drain for the evaporator. Small things like those are important as well.

[@soesterbergblue]

Extremely well done. You're an excellent instructor.

[@pedroparra4539]

Your an idi** YOU DONT KNOW ANY BETTER. THAT GUY IS ONE OF THE WORST INSTRUCTORS (if you can call him that) I HAVE EVER COME ACROSS.

[@happyjacky52]

Thanks for all the info. I took my 2000 Subaru Outback to a mechanic and he wants $2000 to find the blockage in my system. I bought a set of gauges and a temperature gun to try and find the blockage. But I screwed up from the get go. The gauges didn't come with any directions, (ebay) so I didn't close off the yellow hose when I connected the red and blue lines to the high and low ports. So when I opened up the high and low gauges after turning on my engine and running the a/c on high, I could feel pressure coming out of the yellow line. I believe I evacuated what Freon I had in the system. My gauges are reading 0 on the red side and 10psi on the blue, and my compressor clutch will not engage. The clutch was engaging before when I added Freon to the system, and the mechanic never mentioned it not working. So I think it was me who screwed up by not blocking off the yellow hose on my gauge set. Do I need to evacuate the system before adding new Freon to it ? I figure once I get Freon back in the system I will be better equipped to diagnose where the blockage may be. Any tips for locating a blockage ? Scotty Kilmer's video mentioned using the temperature gun. If I need to replace the condenser, should I replace the drier as well ? Thanks for any help and God bless you for helping out your fellow man. John

[@defthopeswell]

Appreciate you taking the time to make this video.

[@michaellorenzo4625]

Thank you so much for creating this video, I was curious how my car's A/C system works. This video provides a clean and easy to follow overview of an A/C system and will be helpful to me as I try to solve my car's A/C problem. Thanks again for the well made video and explanation!!

[@pollycrilly6842]

Hi, great explanatory video! Here's my situation, 2003 Pathfinder, AC hasn't been maintained since new! I did the DIY Can w/gauge thing. But before adding r34 the gauge read 105-110psi way into the red w/car running ! ( I was told do not add at that point, seek professional help) **Story of my life! Anyway, watching a few DIY Utubes, I quickly figured out that I can put gauge on The LOW Pressure tube under the Dust Cap and bleed the pressure down! I did just that, but unlike the utubes, it never put a yellow residue into my white rags all the way down to Zero PSI ! ok, seems easy enough ( I know there is more involved), but shooting for simple fix, I shook up can of r34 and proceeded to fill as directions and several U-tubers directed) I put in all 18oz of the can and the gauge sat perfectly in middle of green area, I reached in window to feel nice fairly cold air coming out of vent!!!! I said PTL and was very happy it seemed to have worked perfectly :-)) ... each day car was blowing warmer and warmer air :-( ... after a week, I was told it was because I didn't fill it enough! ?! I went to Auto Part Store I bought 2 small 12oz cans of r34, I repeated steps above..... Yes, The gauge started way up in the red again pervious adding the 2 cans, I bled it off, put the 2 cans in, the gauge went to the top of the green area on the gauge, I used another gauge from a friend & had same reading! so I know it's probably not a faulty gauge! YAY, I have cooler air blowing into car from vents... but not cold , sure enough 3 days later the AC was a little cooler than outside air My neighbor, doing me a favor works at Sears Automotive, took it in today to see if his Mechanic could trouble shoot it and see if and where there maybe a leak or if any of the components are bad! * Here's the funny thing, instead of me replacing the dust cap on the L line, I kept the cheap-o gauge on it all week and kept raising the hood to see what it read whether it sat all night or ??? After blowing warm and it zooming back up to the red, I bled it down to zero, and watched the gauge climb on it's own! I opened the hood this AM in front of him to grab my gauge and it was in the white area, I showed him. Upon servicing the AC The Mechanic texted that the Compressor was fine and I was lucky not to have blown a seal, for I had overfilled R34 !!! I say B.S. but then I don't understand this as A Trained AC Mechanic should! 1) How could I overcharge it having bled psi down to zero both times previous adding R34 ? 2) Upon being asked if they put dye in to check for leaks, they told me later that they had put the dye in ... (I'm not meaning to be a turd, and reiterate I am No Mechanic but skeptical because from what I understand it's a enclosed system like Brake Fluid system or Coolant on a vehicle! There has to be a leak somewhere, 15 Years and AC blew cold enough to put a sweater on, it worked fine and now it doesn't! Any ideas , Please help this old Veteran out God Bless America

[@thomasstreetman8066]

Thanks for the video. I had a 1989 Honda Accord and the system had a sight glass on one of the components and I could see the refrigerant flow in one direction. I don't recall a vehicle I've had since then that had a sight glass. Thanks again.

[@joshualebf.lugodelvalle2590]

Love the video, helps me to understand more the function of the A/C, keep it up!!!!

[@synkoptik5]

Ok this is my second video I watched from you and let me just say.....God bless you and yours.. Thanks for this! BTW, your good at explaining, good comprehension. It just so happens that my AC is out, blows hot air and I have put freezer stuff but it only lasted a shot time so I'm thinking there is leak but I really dont know much about cars. I will follow the link to your video in which you explain how to check for leaks. Thanks again mate! [On the internet I'm British!]

[@siucbset]

Great Video. However, I think you should have shown two diagrams. One diagrams showing the expansion valve/receiver dryer setup and the other showing the orifice tube/ a/c accumulator setup.

[@Micscience]

I had to give you a thumbs up you did a good job explaining the AC system. Good Luck!

[@myRatchets]

+Micscience Thanks, glad you liked it. Cheers

[@addisoellio]

This video helped me out a lot. I understood the general concept of an air conditioning but I wasn't sure how to locate many of these parts.

[@myRatchets]

+Addison Elliott Glad you like the video, thanks for commenting.

[@steventhepig3173]

God Bless the People with the Gift of Explanation 🙏🏿

[@manuelsalvatierra2940]

South Main Auto brought me here, you guys (along with other) are great. You got a new subscriber

[@peterjd.w794]

Calm man, You good explains and kind comments, I worry Scotty Kilmer talk too fast short explanation.

[@mfsperring]

Good explanation on the differences between orifice style and variable expansion style. Just what I needed thanks.

[@frankbarboza]

How does the A/C system flow diagram look for a vehicle that also has rear cooling lines such as found in a Chevy Tahoe? I've seen a few videos in which the front vents were blowing cold but not the rear. I've also seen a video in which an owner apparently had issues with his rear cooling and instead of fixing the problem, he blocked the lines going to the rear of the vehicle by installing plugs. These videos with rear cooling issues lead me to believe that there is a separate component (and therefore something that can stop performing) that routes the refrigerant/cooling to the rear without effecting the front or else the front wouldn't be blowing cold as well. I appreciate any light you can shed on the subject.

[@joeradi4787]

Great. this is a public service without bureaucracy. thank you

[@ricktaylor1860]

Great job explaining the basic AC system

[@Stefanakos246]

Like your video and your flow chart was spot-on.

[@bradsmith2661]

Forgive my ignorance, but what do you mean when you say moisture at 3:46. Th refrigerant leaves the condenser in liquid state, runs through the receiver/drier which removes contaminants and moisture (my understanding of the word would define that as a liquid, the refrigerant in this case). After the receiver/drier removes the moisture it still leaves in a liquid state. Is moisture in this context defined as condensation? If it is defined as condensation how does the receiver/drier remove it from the refrigerant? Am I missing the concept entirely? Someone please educate me.

[@Peter-pv8xx]

Refrigeration is one of the single most important inventions ever, it revolutionized the way we live work and even play with indoor arenas able to be used in otherwise unbearable conditions, it also has numerous health benefits, can you imagine being in a hospital stuck in a bed for days or weeks in the sweltering heat? We owe a lot to Mr Willis Carrier.

[@mp4338]

KIA RONDO. The compressor leaks under frame, tested w/ink on the freon. You have an expreriece w/this?

[@michaelrj9]

If you have a new receiver drier how long can it be open to the elements. A day, week, month etc before it needs to be replaced. I'm in the process of installing a complete new system and wondering if it takes too long to get everything plumbed, evacuated and charged. It looks like the receiver drier has caps on it right now but after I remove them how long does it last. Thanks

[@JonMarc22]

My freon leaks out over the winter every year. So I know I have a leak. Therefore outside forces have got in the system right? Do I need a full new A/C kit? Or what do you think I need to replace? Thanks

[@SaraJAwesome]

Fantastic video!!!!!!!!!! You’re amazing! Love the visuals! I’m having issues with my Tesla model 3 Air conditioner and I’m trying to explain to people on my channel and learn myself how the A/C system works… this video is perfect! Do you have any videos that talk about the Evaporator drain from the A/C and problems that can arise from having debris in the system and bad/ or clogged evaporator waiter drain? Thanks! I will link this video on my own channel! Excellent work!

[@raymedorio1930]

Hey I have a question My 04 dodge ram 1500 4.7 has the little ac condenser and you know it has his own cooling fan This fan will work when the ac is on only Or it will runs with the heater too? Thanks

[@edwind4842]

Hi, I have a question I have a couple of cars I'm getting power on pin 30 and pin 86 the other 2 is ground when the relay is removed but the only way I can get the ac clutch to engage is if I bypass it , do you where I should look for the issue to get to work the right way ?

[@feboogi]

ive checked all connections all acuators are functioning...any idea why I am getting less airflow on passenger side vents, I assumed there was one channel of flow that split two ways but is there actually a blend door for driver and passenger if only one climate control? Im stumped

[@eduardodaquiljr1621]

Sir in evaporator where the airflow starts,is it from the side where TVX is nstalled or after the tvx/

[@jessehndz3124]

Hey Brother awesome instructions. question do you have a 2001 Dodge Ram 1500 3.9L ac wiring diagram? my 10amp fuse keeps burning out. Do u have any suggestions?

[@knunne1]

Great video, South Main Auto sent me over with a high recommendation on your videos and I can say I was not disappointed. Thanks again for a great video!

[@mitchell9345]

So South Main Auto is having their customer do the work? Harsh bro, but I guess that’s the cost of doing business eh?

[@FreeKanal]

Hi can u tell me what decide how long compresor cycle is ? Is it only Evap temp sensor? Or something else too

[@k0b128]

I had to do a double take because I thought this was Engineering Explained lmao. Nice video.

[@ramesherrabolu1590]

Very well explained how the whole thing works

[@yashaswisharma9064]

I like the way you presented this video, good job.

[@johnteplir7874]

Thank you for your a/c videos. Though I’ve worked on lots of cars, I never worked on an a/c system until the system in my 2005 Silverado died. Your videos clearly explain how a system works and what to look for when it doesn’t. Thanks again.

[@thomasschwabe7352]

Great explanation bro, really informative. You sound like a really good and honest Tech.

[@henrysalem5516]

Great video on how the system works in general, thank you. I have 1986 190e which the A/C doesn't work, the compressor doesn't comes on. I changed the original compressor and the dryer to 134A compatible, changed the push-button & A/c relay, and the pressure switch, still no luck, would you direct me how to fix it. Several local mechanics has charged me to the nose, yet no A/c

[@suheilrana767]

hi do you have any videos on lpg systems I've got a vauxhall zafira which has factory fitted lpg system and when I switch to lpg the engine starts revving at high speed thanks

[@intellectracoon]

What if the ambient temperature around your car is above 48C 120F and the condenser fails to condensate the refrigerant to liquid form ?

[@hamdanalharbi2206]

does changing the ac compressor and condenser to a larger one makes the ac colder?

[@davidmontes6861]

My ac only works only on 4 and it makes a scraping noise...I was still using it, but then some burning somewhere starting blowing burned smoke into the cabin...any idea what the problem is? What might be burning? TY.

[@donalddean2113]

Well done buddy nice video, love it thank you for taking the time to make it.

[@premsingh-spreadlove4814]

I really appreciate this video which helped me to know abut car AC. it is good to know abut car AC system . can you put more videos regarding HVAC faceplate and HMI. how car heating system works, how engine cooling system works with the help of coolant pump. Thanks

[@OldSchoolNoe]

Simple, now I gotta go locate these in my car.

[@1234prettygal]

do you have to or should replace the ac condenser when replacing a ac compressor?

[@mustafaar7899]

hello my car ac compressor on and off every 10 sec I check the gas and it charge because when car is off low pressure 120 psi do think type of r134a which available are bad type cause this problem or the condenser or thermostat or what u suggest for me to do

[@kwiz8848]

This guy knows his stuff 👍

[@davidvalleysr.8223]

This and those post like this one is excellent, however we find tons of videos like this but you can't find one single video explaining what to do to troubleshoot bad control or actuator wiring, we have enough video's on the web telling us about under the hood, we need a break down on the BCM and EMC and how these items work with your car or truck HVAC system including the head or what most of us call the control unit., if you can do a video on this you can easily do a video on what would cause an actuator to stop operating as it should.

[@Neurocidal]

Great information man, very well put together, easy to understand, thank you for sharing.

[@tlegg5338]

My ac drier has the word (in) on top of it my question is do you put it on coming through the low pressure side or the high?

[@Misfits89]

He needs to be an instructor at some school

[@nickw6617]

what a great breakdown, your absolutely right

[@alamgirr1996]

Good job from Bangladesh ❤❤.

[@marquittawinfree5206]

If you ever update your video... I appreciate the video and white board! However... could you lay out some old parts on a table to which to point as you get to that part on the drawing? I'd really like to SEE the actual parts (even though I know they will vary somewhat). How does the orifice tube or expansion valve communicate? I don't see wires from that area to the evaporator or compressor... And you might mention, " In case you forgot...the condenser equals pressure, and pressure equals heat... It's like the molecules are fighting for space." Thanks again!

[@1991esoj]

thank you so much for dropping this knowledge ,I will watch more of your videos now

[@djchief93]

Great video my guy 👊🏻👊🏻👊🏻

[@Akbar-dq6vs]

Very well explained. Thank you so much.

[@Joanna-A7227]

My clutch flops. Now the bearings are grinding. I can't get it fixed until Nov 4. It makes a loud noise. The compressor needs replaced. I'm afraid to drive it because I think I will damage something in my car. It's really loud. The AC is off, but the noise from the bearings grinding is really loud. Is it ok to still drive?

[@Mandla_Tapower]

I've got a squicky noise that sounds like its coming from the deshboard when I turn AC on, othwise it works perfectly, what could be reason for that squicky noise?

[@alanamos5158]

I had a voltage drop and I found at least 1 from license tag light. And I had a chirping noise and it only makes the sound when I turn AC on. I've got starter rebuilt and 2 alternator's I put on and it's not losing as much voltage now. Could it be the AC relay but I just switched 2 the same. Please help me. Oh I cleaned battery cables and al grounds

[@TrungLe-rq5dj]

My 1993 Chrysler Town country...turn ac on but it stays off. But when the engine warmed up the cooling fan turn in and simultaneously the AC comes on..after a couple minutes the cooling fan goes off , the AC off along with it until the fan Runs again...I was thinking about hooking up the fan to 12v with a switch so I can turn the fan on so the AC would come on with it anytime I want..can It be done or will it burn the AC compressor...can you help

[@NGGamer-nb6bu]

If I have a chipped / damaged carbon fiber part in my engine bay, am I at risk of getting the particles into my car via the AC?

[@nataliecarvajal8492]

I have a question. I'm trying to diagnose what is wrong in my cars ac and I don't know whether it was the condensor or compressor. Ac turns on but it's stuck on economic mode with warm air coming out. 2002 audi a4 1.8t. Any help? I put more coolant and nothing happened.

[@johnnymartinez42]

Awesome videos! I have a question I own a 2001 vw golf German made, just replaced ac compressor, dryer and expansion valve, also both fans in front, I can hear the fans engaging to high speed but my ac won't blow cold unless the car is in motion. How do I know for sure I need a new ac condenser? Thanks a lot my friend.

[@myRatchets]

Johnny Martinez if you replaced the compressor due to it seizing you probably have metal shavings blocking the condenser. But check your pressure readings first to verify but also double check and make sure both fans do indeed work and also you have to dirt or debries blocking your condenser up front. Also make sure you have enough refrigerant in the system. gl

[@bigdawg8769]

Hi when u drive my ac cools but when am just parked it won't kool the fan works fine an the compressor also when I rev to 2000rpm in idle mood it looks also any idea what might be wrong

[@louislaplante4838]

Great knowledge and experience 👏

[@carlosmanfernandes]

Does the car cooling system has any high or low pressure switches on both lines? Thanks

[@only7772]

Yes, Depending on the vehicle it may have both.

[@crawfordoverton3299]

Some minivans for 2 evaporators is there a way to get it to run at a100 % I find many have problems doing this type system. What I'm asking is if there is a trick?

[@nicolassanchez4786]

Great video! I was wondering should I replace the receiver dryer when I replace the AC compressor in my 99 Toyota 4Runner? if so any advice on how to replace the dryer?

[@only7772]

Yes, Always replace both together. The system may need to be flusher first though.

[@ocramjkm100]

Hi and thank you for your information really good information., I have a question i have a 2014 chey sonic 1.8 i put the gauges and what happens is when the car running both low and high side gauges shacking what is that Mean? and thank you in advance

[@Blackford86]

Hey Boss I have 2007 Saturn Hydrid Vue I have no cold air when I turn the A/C on I don't even hear the clutch come on. I bought one of those auto zone refrigerator bottle and it when to red 689/100. Also with this Hyrid the compressor is on the right of the engine compartment no belt so I don't have a clue how the thing even works. Do you have any ideas. Thanks

[@trevorbyron9448]

Does any lines pass through the transmission? .I smelled gas when I opened a wrong bolt in transmission...I closed it quickly.

[@DanielRodriguez-vh3dz]

I got a 02 ford f350 I had a clogged orifice tube & i changed it & now it's blowing cold air but it's on & off. intermittent. Any idea what that could be?

[@KThach.]

Do some condensers have the dryer built into them? I was told my 07 RDX had to get a new condenser because the dryer is also part of it when the ac compressor was swapped. Not sure if what they told me was true though.

[@raquelojeda8311]

So just to clear a doubt when the high pressure gas is leaving from the ac compressor into the condensor, the gas is turned into liquid by the atmospheric air that is being cooled by the ac fans am I in the correct or is there an actual device that performs that function?

[@yhyaalree6661]

dear i have sensor ac evaporator problem. What happens if I put a 10k resistor in place of the sensor?

[@Ryan-mn2dd]

Wow, thanks for making this. Very good. I learned a lot!

[@NhelBal]

hello!..can you make video how dual ac works..

[@brianpang6140]

I have a 1994 Mercury Villager. and my AC compressor totally freezed and could not be turned with a wrench. The belt got burned and broke off as a result. Due to that malfunction, what are the steps to repair the AC unit? It seems that I need to replace the AC compressor. Do I need to flushed my system? Do I need to replace the Condenser? Do I need to replace the Receiver Drier? Any metal debris gets stucked in the Condenser ? Thanks!

[@myRatchets]

+Brian Pang Change compressor, condenser and receiver/drier. Very good idea to flush the system too, but most of the metal shavings from your compressor are likely in your condenser and/or receiver/drier. GL

[@shermuhammed5564]

Could you kindly do a video on a Isuzu Bighorn's Air conditioning blower removal, cleaning and replacing it together. 4XJ1

[@FD-dh2fu]

So your evaporator is also the heater core? If you change let’s say your heater core or radiator your saying you should also change your receiver dryer??

[@markolden6032]

Have a odd question, I bought a new line from the condenser to the evap, but it was slightly different it had a built in oriface tube built in real close to the evap. But my other original one was located jamed down at the condenser. Didn't like this way I thought the built in one was neat. But new line came with high pressure port instead of the low like the original. So I thought maby ok so I just put a high pressure end on my low pressure hose. But could not get suction to add freon. Is it because I'm trying to add freon before the oriface???anyone know

[@jayorcullo2300]

next video Pls do a wiring diagram for car AC..ty I really appreciate your video

[@BRANDT409]

Hi. My ac button won't switch off, so it's always running on auto / always running.I checked the fan speed controller, but that's not the problem. Ii must be circuit board in the dash right? Anyway I left the fan speed controller unplugged, so the air con doesn't blow anymore. But I think the compressor will still be running right? So I unplugged the Compressor. After that, I noticed that the 2 fans in front of the radiator are still blowing, even when engine is cold & only just started the engine. Why are the fans still blowing? (2003 2.0 Nissan Primera Wagon)Thanks

[@tabs-zv4ln]

one question sir, why there is no thermostat in your system? is it in different stage of A/C? newbie here and new subscriber in you channel..thank you for the explanation. Nice presentation sir.

[@gabrielseaff487]

Excellent video and information. Thank you

[@mitchell9345]

Great video Facundo!

[@michaelbravo1110]

Very good video man ! Well detailed ! I have one question so i everytime my car is on and i put the recharge guage on it and turn the ac on it goes down to 0psi but then i turn it off and presssure goes back up but still no cold air i changed the compressor ,expansion and the only thing i have to replace is the drier and maybe condesor any clue on what you think this issue might be ?