Literally this is 1 hour worth of College Lecture in 15 Mins. Thanks for this channel. I m not a student by the way, I just wanted to learn about cars and as result of my search on you tube, I stumbled upon your channel. Didn't have any regrets. Keep up this work far as you can sir, This is really educational. Thank you again.
Best view of this system I've ever seen, bravo! I didn't realize it had its own CAN bus system, what a complex process. I really like the snappy information delivery you show here....
Amazing how, when explaining the way things work in your videos, it comes across as if you designed and made the components yourself. No second guessing, and the information flows without a hitch. Great job and always appreciated
This video is fantastic, I understood the basic function of each component, but to have the air box opened up and see how each path works is exactly what's needed to learn!
I comment on very few videos for one reason or another, but your video deserves my time and praise. I went through formal tech school , and was a Master Cert Auto Tech for 19 years. A large part of what you demonstrated in 14.5 minutes took most of us pros years of figuring out. There is nothing like hands on, well articulated, music free, and accurate information. Thanks.
I just want to say thank you for taking the time to make your videos!! I am an automotive instructor and since we are on quarantine I have been using many of your videos to teach my students. You are very knowledgeable and my students are learning a lot from you! Keep up the good work!!
Super break down of the system. I do not drive any more but I am impressed how much thought went into the system. I love the mechanical side of it with the vents being moved on cams and levers. Super video as always.
You have a very broad understanding of the mechanics, electrics and physics in general behind this system. Clearly well schooled. Thanks, very interesting indeed.
I have always worked on cars both everyday cars and my race cars. However. I started carrying an old toothbrush in my pocket, and when I have a problem I take it out and start explaining stuff to myself, pointing at this, and pointing at that. My wife thinks I have lost my mind, but it works! LOL! Thanks for the videos, very educational.
I love my cheap car's MANUAL SINGLE-ZONE HVAC system. It has physical lever for recirculation control, for example. No motors, no extra wires, far fewer things to go bad.
@@catsspat That's the same way the automatic climate controller regulates the interior temperature whenever it can't control the compressor displacement. It first acts on the fresh air flap and then on the heater flap/valve.
@@foxtrot312 2003. The only AC electronics is the ECU, which decides when to engage the compressor's clutch. There's not even an evaporator temp sensor (pneumatic control valve on compressor takes care of everything).
Beat that TH-camrs! Awesome breakdown of the HVAC system. I just hope mine never has an issue because that looks like alot of hard work tearing it down. You show alot of understanding and I'm sure you must be able to diagnose problems really well because of it..
The bus is likely a LIN serial bus, which is 1 wire + power. It is used in place of CAN bus for accessory tasks and smaller sensors. It's also often used for the window controls and other simple dash controls. IT can be deployed using simpler/cheaper microcontrollers than CAN bus where data rate is not very high such as HVAC system in this video. Keep up the great work!
@tveilleux is right. It is definitely not CAN. The bus feels like LIN but based on the diagram shown in the video it might not be 100% LIN. Nissan or the part supplier might have tweaked it for their needs.
Well done! Not sure how I missed this video. Great job explaining the system as a whole. Beginning of video (dash tear down) I saw snow and ice, then tulips & green later on. Seems you have weather Like I do on the other side of the pond (Erie). Dye in system----must have had a leak prior. UV & yellow glasses great stuff to find leaks once dye injected & system ran. Always appreciate your time to make these & you using your bro's green shirt to mop up green dye. He'll never know if you get it back in dresser in time.......brothers. That is so familiar to me. Once more, thanks!
Really good video. Only one mistake in regards of communication with servo motors. They are on LIN network, not CAN network. CAN would have 2 communication wires (CAN LOW, CAN HIGH) plus Power and GND (Total 4). Your is for sure LIN. Subscribed!
LIN is much simpler and slower then CAN, however still interesting network type. You can learn a lot from materials released by suppliers like BOSCH. If you want to go really deep on it, I can suggest books or BSc/MSc projects papers. Godspeed!
i wish i meet people like You in my life and learn sometiing from them, Your videos are very helpful, i wish You will making more vids about how it works and how to fix something, thank You so much
As always well done Speedy! I had one of those actuators fail recently in my Lexus which then blew outside air on just the driver's side, and cool air everywhere else. Rather than pay $80 for a replacement, my son figured out that by removing it, he was able to position the flaps to just allow inside air.
@@speedkar99 not sure what mode it was in I just know that the Driver's side was not cooling. Removing the actuator and manually positioning the vanes took care of it. We tested the actuator with the cover off and found that the motor doesn't turn. We could probably replace the motor or get an actuator out of a salvage yard, but this works for now.
I legit just found your channel and it couldn’t have been a better time. I was looking to find a mentor who could tell me how to go about diagnosing cars with problems. Bumped to bumper, exterior, interior, powertrain and engine. After finding you I figured I’d ask the fisherman how to fish instead of fishing for me. So with that being said....where can I learn about cars without going to school?
speedkar99 Thanks for the reply! Really appreciate what you do! I definitely plan on buying your brothers socks only if you continue to make more videos.
i am amazed - and grateful! thank you for showing us how this all works, you really know your stuff. i want to especially want to thank you for tearing everything down - it's like I was right there taking this all apart myself. it makes it so much easier to understand. a really great job on so many levels/aspects. kudos!
It might be the same color, but it will still smell like Band Aids/bird droppings (yup, PAG compressor oil, that's what the green stuff really is, smells exactly like this)...
@@speedkar99 Yeah, man. No one does it like you. There are videos explaining car stuff with computer generated images, but none are as practical as yours. It is much easier to understand how things work from your videos. And on top of that, you have great sense of humor and your speech is clear and precise.
This video was another clear and comprehensive description, way to go speedkar99! Also, modern automotive HVAC systems are so complicated! Wow, you should see my '77 Toyota FJ40.
Depends upon the car, my '03 Vauxhall Agila A is also primitive compared to this. There's not even an evaporator temperature sensor, because the variable compressor does everything on its own so that the evaporator never freezes, and another nice feature is that the evaporator will only get cold enough to provide comfortable air depending upon the weather. No electronics at all here, just a cleverly engineered compressor control valve. Too cold? Rotate the heater knob a bit until comfortable.
Great informative channel. In my 2019 Nissan Patrol Y61 the AC is very cold when car is moving but when I parked & engine is on AC become warmer. Well can you tell any suggestions to make it constantly cold.
Thanks. I find many car AC systems are like that, more RPM means more energy for the system to cool down since it does suck alot of energy off the engine
We love your videos for going through dissecting the components and explaining the theory and operation. You have all the ingredients to be a good teacher and a mechanic. But can you make a video longer and explaining troubleshooting. We love to watch your videos and don't squeeze everything in 15 to 20 minute frame. I watched all your video and if you can slow and do more explanation. Specifically video on transmission and torque converter. If you can make two versions of the same video one for the ones who want to refresh and one for us who want more explanation and never opened dash board of a car. I will me watching your videos when I open mine Thanks
Thanks for the compliment. Great suggestion but the audience here wants information and fast without wasting time. That's why I edit to be as short and to the point as possible. Any longer and I might as well open a university haha 🤣
9:14 that's the TXV mounted on my European MPV (tried to find a scrap one to no avail, and the original one is like 130 bucks at the dealer) and in your video i'm able to notice some nicks on the valve seat, am i right? Also, in my channel i disassemble another one made by TGK, and there are no nicks on the seat, but, even though the ball is able to seat completely, the valve still never closes even if i completely adjust that little plastic nut to the closed position and then freeze the power head (that's a "cross charged" valve and you find it with variable displacement compressors and rotary compressors, i can link some patents that show how these ones work; on scroll and vane compressors, they apparently help to keep the evaporator from freezing by keeping a little flow of liquid so to prevent the suction pressure from going down too much; on variable displacement compressors, they keep the control valve from malfunctioning and also keep the compressor lubed; the nicks on the valve seat may actually do the same thing)... also, in the TXV i disassembled, the ball is attached to the metering rod... anyway, thanks for disassembling it!
I didn't pay attention to any nick's in the valve seat but that would be an interesting way to let things be lubricated. This system had way too much green dye
@@speedkar99 Yes, it also keeps things lubricated even when the evaporator is cold and the TXV is closed (practically speaking). Rear seat evaporators, for example, have nicked seat TXVs so that the oil doesn't pool right behind the TXV when AC is on but the rear blower is kept off. Unfortunately, TXVs that stay open, either because they're cross charged or nicked, also allow liquid refrigerant to migrate to the compressor while the system is off, causing a lot of noise (scroll, through vane, that sometimes start up noisily for this reason) and performance (variable displacement piston compressors, that sometimes take a little more time to go into full displacement than usual) issues...
nice video, btw is there anything stopping air escaping from the evaporator drain, when there's water dripping it doesn't look or feel like there is of any forced air coming out? But then lots of people clean their ac by putting foaming cleaners through the drain hose.
Good question, i guess the blower fan and evaporator box is designed to take it into account so that any airflow loss is minimal and some air actually helps the condensate water drain away. I confirm there's no valve on mine, but the drain hose is still pretty narrow, and it's shaped not unlike the trapway of a siphonic toilet bowl. I've never put a finger on it with the blower on by the way
the green "stuff" supposed to be a leak detection agent. So this system had leeks prior and someone used the liquid to see (with UV) where it leaks ...
Sir I am Eric Ang from the Philippines. I have a Mitsubishi Mirage G4 2018 model. The AC runs under an HVAC SYSTEM. Old school AC we put thermostat on half cold level so as to prolong the life of the compressor and for fuel efficiency or save on gas. For the HVAC SYSTEM is it true that it is the other way around? I mean is it true that if you want to save on gas and not keep the compressor always pumping, it is more beneficial to set the thermostat on full cold? , so as not to blend the cold gas from the evsporator with the hot air from the heater core? Pls enlighten me if this is true or a myth. Thanks and more power.
Myth. The most important thing is to always maintain enough refrigerant charge to allow enough oil to return to the compressor at all times. And to ensure the condenser is able to reject enough heat (fans, air dams must work correctly and condenser fins must be kept clean; a fan motor or fan clutch can be bad and spinning the fan way slower than intended even when it isn't making strange noises) to ensure a good enough compression ratio. All compressors, even ones never ever mistreated, do wear eventually. Want to keep the evaporator cold enough? Run blower at low speed. But the more the clutch cycles in order to prevent the evaporator from freezing up (keep in mind that automotive expansion valves are already calibrated to stop the evaporator pressure from dropping down too fast and therefore the evaporator fin temperature from reaching freezing temperatures too fast, by means of a cross charge that prevents the evaporator from starving at low evaporator pressures), the more the clutch wears.
Perfect explanation as always. Would like to ask just one simple question: How does the system work to minimize the compressor usage (or power consumption from the engine) when you select a higher temperature as it uses a mixer and not an on/off principle? Or it doesn't? Thank you!
I'll try to answer. Since the car's compressor displacement is externally regulated by means of electronic control, the control valve solenoid on the compressor will be actuated so to keep a higher suction pressure and the compressor will reduce its displacement earlier as a result, keeping the evaporator warmer. If the compressor control valve is of the internally controlled mechanical type instead, a lower discharge pressure will act upon the valve's evacuated bellows (due to the lower ambient temperatures) and they will be able to expand earlier, achieving the same exact result, that is, a warmer evaporator and less power required to turn the compressor on average.
Great video, are the block expansion valves adjustable like in your video to allow more liquid to flow into evap? Trying to lower the vent temp to 40° from 45°.
That little nut controls how much the evaporator fills up with refrigerant indeed, but i highly suggest you to never touch it or you may damage the compressor (i.e. if you open it too much you may slug it with too much liquid, or if you close it down too much you may deprive it of cooling and lubricant). If you feel the TXV has some issues, just fit a new one. By the way, the TXV will never control the evaporator temperature. It will only control at which temperature the refrigerant will exit the evaporator and this is meant to prevent it from exiting the evaporator's outlet as a liquid, even though, with this valve, the superheat will progressively switch to 0 as the evaporator cools down, and as a result some liquid refrigerant will start leaving the evaporator (this is meant to keep the evaporator pressure from dropping down too fast, avoid interfering with compressor control valves and keep the compressor lubed). The minimum evaporator temperature is controlled either by a pressure switch, an evaporator temperature sensor or a compressor control valve. What you have in mind will, at most, control how fast the evaporator becomes cold, but again, don't touch it. Look elsewhere to solve your problem.
I would assume the needle spring will weaken over 10 years or some of the gas leak out of the temp sensor disc. A weaker spring would allow the needle to open more allowing more liquid and faulty disc would not push needle down enough, I would say the later is more likely to happen. TXV are very cheap and if I gain 5° more cooling its worth it, only negative is system needs to be discharged.
@@metalhalide4043 The power charge will never leak out of the disc, it's a tiny amount, there's also some adsorbent so that the valve won't "hunt" superheat. I obtained a 20 year old one i like to play with, i've disassembled and reassembled and tested it again and again, and it opens and closes perfectly. On my channel i show how the ball closes the valve when you spray liquid canned air upon the disc... never seats fully closed though, because it came from a car equipped with a Sanden SD6V12 variable compressor...
@@metalhalide4043 TXV systems never cycle on suction pressure that i know. Only CCOT systems do that. TXV systems only cycle on the output of a evaporator temperature sensor, if the compressor is of the cycling clutch type. With a fixed displacement compressor, very low suction and high/normal discharge means stuck closed TXV, normal/low discharge and high suction means stuck open TXV. With a variable displacement compressor (for example Harrison V5, Sanden SD6V12), pressures won't tell you much because the compressor is able to adjust working pressures. Noise is more of help, loud groaning noise means low displacement operation and this tells you of a compressor that is trying to increase a very low suction pressure (created by a stuck TXV for example) by fully destroking. Stuck open TXV is instead indicated by frost on the suction pipe. Then there are externally controlled compressors. A lot depends upon the compressor...
@@speedkar99 Thanks. So if there is a bypass valve, there won't be coolant going through? Mine is a Camry, I touch the pipe that's going to the heater core in the engine bay, it seems hot.
I've always been wondering - when you turn the HVAC off what happens to the coolant in the heater core? Does the coolant still flow through the heater core basically making it super hot, or are there some bypass valves to redirect the flow around the heater core to prevent all the plastic in the air mixer from overheating?
Some vehicles have a coolant shut off valve outside the firewall that blocks the flow of coolant thru the heater core. This one doesn't appear to have it. I don't think the heater core can get hot enough to melt the plastic housings
@@speedkar99 ah, ok. Thanks! I noticed in my car (regular HVAC controls with knobs, no climate control) when I turn the vent selector to 0 I still get a little bit of hot air coming from the dash vents. I would assume that means that there's no coolant shut off valve in my car. Anyway, thanks for another great video! Straight to the point as always. And I absolutely love your toothbrush pointer haha.
In my Vauxhall Agila A there's no heater flow valve. Water is always going through it. The heater flap takes care of everything and in the summer, when the heater knob (directly connected to the heater flap through a Bowden cable) is on the cold position, i still get ice cold air at the vents even when coolant is hot. Also, running AC also seems to unstick the distribution flaps in the heater box, which tend to stick whenever i've left the car in the sun for a long time.
Learn how manual HVAC systems work here:
th-cam.com/video/04MlTepEIz4/w-d-xo.html
Literally this is 1 hour worth of College Lecture in 15 Mins. Thanks for this channel. I m not a student by the way, I just wanted to learn about cars and as result of my search on you tube, I stumbled upon your channel. Didn't have any regrets. Keep up this work far as you can sir, This is really educational. Thank you again.
I'm so glad you can learn from my work. I do this as a passion, maybe one day I could reach professor level
I love your videos man. You teach so much, yet never get bored during the video because you give that special touch of funniness :)
Thanks I appreciate that
That used tooth brush has been exposed to more knowledge than most mechanics these days....
Very true
From his brother
Excellent video! This is the most in-depth explanation I ever seen.
Thanks.
I got alot more where that came from 😉
Best view of this system I've ever seen, bravo! I didn't realize it had its own CAN bus system, what a complex process. I really like the snappy information delivery you show here....
Thanks
Yes I didn't realize it until I researched why each motor has only 3 wires and found a good explaination in the repair manual
Some vehicles use the lin bus but operation is the same.
Amazing how, when explaining the way things work in your videos, it comes across as if you designed and made the components yourself. No second guessing, and the information flows without a hitch. Great job and always appreciated
I appreciate the feedback. Thanks and I'm glad you find it interesting
This video is fantastic, I understood the basic function of each component, but to have the air box opened up and see how each path works is exactly what's needed to learn!
Glad you appreciate it! Thank
What I like best is the hi-tech pointer - works pretty good and inexpensive
Agreed
As always a brilliant video. Never knew how a canbus system worked. Thanks for explaining it in an easy to understand way.
Thanks. I didn't know about the CAN bus system either. Quite complex
Yeah...that was so easy to understand that it was brilliamt.
I comment on very few videos for one reason or another, but your video deserves my time and praise. I went through formal tech school , and was a Master Cert Auto Tech for 19 years. A large part of what you demonstrated in 14.5 minutes took most of us pros years of figuring out. There is nothing like hands on, well articulated, music free, and accurate information. Thanks.
The single best video on automotive HVAC that I've ever seen! Kudos! And thanks for what was, essentially, a master class! A+!
You are welcome! Glad you appreciate my work
Im in an automotive program now n i learned more in this video than i have in 3 weeks at school
Dude you have the most in-depth video I have seen on TH-cam ..I enjoy and learn from watching your videos...thank you my friend..
I just want to say thank you for taking the time to make your videos!! I am an automotive instructor and since we are on quarantine I have been using many of your videos to teach my students. You are very knowledgeable and my students are learning a lot from you! Keep up the good work!!
Glad to know my videos are being put to good use in the classroom! Thanks
Super break down of the system. I do not drive any more but I am impressed how much thought went into the system. I love the mechanical side of it with the vents being moved on cams and levers. Super video as always.
You have a very broad understanding of the mechanics, electrics and physics in general behind this system. Clearly well schooled. Thanks, very interesting indeed.
Thanks
I learn as I go, and by reading up...I didn't go to school for this
It's motivation and dedication that results in education. The rest is just there to facilitate if you are interested.
I have always worked on cars both everyday cars and my race cars. However. I started carrying an old toothbrush in my pocket, and when I have a problem I take it out and start explaining stuff to myself, pointing at this, and pointing at that. My wife thinks I have lost my mind, but it works! LOL! Thanks for the videos, very educational.
I'm glad it helps and toothbrush inspired you
The only video about "how the dual zone climate control works" I got on TH-cam. Thanks dude.. 🔥🔥 Learned a lot from this video. Keep it up... 👌👌👌🔥
I always wanted to know how the dual zone setup works too so I had to open it up to find out how!
Man I love all your videos!! The great info and the jokes about your brother are perfect. One of my favorite channels now, keep it up! Love ya!
What an amazing display.. Best 15mins. Kudos.
Amazing! Thanks
I love my cheap car's MANUAL SINGLE-ZONE HVAC system.
It has physical lever for recirculation control, for example.
No motors, no extra wires, far fewer things to go bad.
True but sometimes those doors get jambed or break
@@teravolt6113 Yup, a cheap Honda Fit/Jazz. I never considered using recirculation lever to control temps. I think I'll stick to ON/OFF positions.
@@catsspat That's the same way the automatic climate controller regulates the interior temperature whenever it can't control the compressor displacement. It first acts on the fresh air flap and then on the heater flap/valve.
How old is your car to not have electronics in Ac?
@@foxtrot312 2003. The only AC electronics is the ECU, which decides when to engage the compressor's clutch. There's not even an evaporator temp sensor (pneumatic control valve on compressor takes care of everything).
Liked your tear-down videos because it contains technical information. Job well done. Thanks.
Thanks...I try to balance practicality with theory
Excellent work. 2 years ago I opened a compressor from the ac system in a car just to see what was in it.
Me too
This is the best video explanation on how components in HVAC work. Excelent job! Thanks for this amazing video. 👍
You are welcome!
Love the sliding flap designn on the air distribution system. By the way, you must have great neighbors!
Neighbors were good
Beat that TH-camrs! Awesome breakdown of the HVAC system. I just hope mine never has an issue because that looks like alot of hard work tearing it down. You show alot of understanding and I'm sure you must be able to diagnose problems really well because of it..
Thanks for your kind feedback. You are right, the HVAC system looks complex and labour intensive but once broken down it's pretty straightforward
It is i just did mine itz very tedious work
The bus is likely a LIN serial bus, which is 1 wire + power. It is used in place of CAN bus for accessory tasks and smaller sensors.
It's also often used for the window controls and other simple dash controls. IT can be deployed using simpler/cheaper microcontrollers than CAN bus where data rate is not very high such as HVAC system in this video.
Keep up the great work!
Thanks very much for that information, I didn't know about that. I'd love to dive into Canbus programming some day and learn more!
@tveilleux is right.
It is definitely not CAN. The bus feels like LIN but based on the diagram shown in the video it might not be 100% LIN. Nissan or the part supplier might have tweaked it for their needs.
may god bless you my brother. you deserve all the best !
Thanks for your wishes
This one is a classic my friend... Thank you for the great work
Well done! Not sure how I missed this video. Great job explaining the system as a whole. Beginning of video (dash tear down) I saw snow and ice, then tulips & green later on. Seems you have weather Like I do on the other side of the pond (Erie). Dye in system----must have had a leak prior. UV & yellow glasses great stuff to find leaks once dye injected & system ran. Always appreciate your time to make these & you using your bro's green shirt to mop up green dye. He'll never know if you get it back in dresser in time.......brothers. That is so familiar to me. Once more, thanks!
Thanks boss, always great videos from you.
You are welcome. Please share!
Man. That's a lot of work bro. Nice job explaining
Thanks. Glad you learned something
Man what a good video!
Thank you
Really good video. Only one mistake in regards of communication with servo motors. They are on LIN network, not CAN network. CAN would have 2 communication wires (CAN LOW, CAN HIGH) plus Power and GND (Total 4). Your is for sure LIN. Subscribed!
Thanks very much for the info.
The repair manual actually calls it a LAN system.
I'd love to learn more about how these protocols work!
LIN is much simpler and slower then CAN, however still interesting network type. You can learn a lot from materials released by suppliers like BOSCH. If you want to go really deep on it, I can suggest books or BSc/MSc projects papers. Godspeed!
THIS GUY IS GENIUS !
Really 🤓
i wish i meet people like You in my life and learn sometiing from them, Your videos are very helpful, i wish You will making more vids about how it works and how to fix something, thank You so much
You are welcome so much 😊
My guy is back!!!. Let me watch this one and see if he mentions ""my brother's toothbrush"" in the video.
T-shirt this time 😏
@@speedkar99 He won't notice the A/C oil. :-)
If anything the green dye will make his brothers green shirt keep its green color for longer.
As always well done Speedy! I had one of those actuators fail recently in my Lexus which then blew outside air on just the driver's side, and cool air everywhere else. Rather than pay $80 for a replacement, my son figured out that by removing it, he was able to position the flaps to just allow inside air.
So it's stuck on recirculate?
I think I'm having the same problem with my Lexus GS too
@@speedkar99 not sure what mode it was in I just know that the Driver's side was not cooling. Removing the actuator and manually positioning the vanes took care of it. We tested the actuator with the cover off and found that the motor doesn't turn. We could probably replace the motor or get an actuator out of a salvage yard, but this works for now.
Man you're just the best. Informative, concise and funny. I'm a subscribe
I legit just found your channel and it couldn’t have been a better time.
I was looking to find a mentor who could tell me how to go about diagnosing cars with problems. Bumped to bumper, exterior, interior, powertrain and engine.
After finding you I figured I’d ask the fisherman how to fish instead of fishing for me. So with that being said....where can I learn about cars without going to school?
I learned by experience....bought a car and took it apart...that's the best way to learn.
speedkar99 Thanks for the reply! Really appreciate what you do! I definitely plan on buying your brothers socks only if you continue to make more videos.
i am amazed - and grateful! thank you for showing us how this all works, you really know your stuff. i want to especially want to thank you for tearing everything down - it's like I was right there taking this all apart myself. it makes it so much easier to understand.
a really great job on so many levels/aspects. kudos!
"I'll wipe this up with my brothers shirt...it's also green so he won't notice" That might have been the best line in all your videos : )
Haha
The coolant matches his shirt
It might be the same color, but it will still smell like Band Aids/bird droppings (yup, PAG compressor oil, that's what the green stuff really is, smells exactly like this)...
Great video...very detailed explanations..thanks
You are welcome
You are one of a kind on TH-cam!
Am I? I barely watch TH-cam to know what's out there...
@@speedkar99 Yeah, man. No one does it like you. There are videos explaining car stuff with computer generated images, but none are as practical as yours. It is much easier to understand how things work from your videos. And on top of that, you have great sense of humor and your speech is clear and precise.
Amazing. Absolutely amazing.
Awesome Thanks
never knew so much tech is behind such apprently simple task of cooling
I agree! It's mind boggling
Zero chance you put it back together before your parents come back home.
I just tossed it 😃
Especially the heater core and the evaporator.
This video was another clear and comprehensive description, way to go speedkar99!
Also, modern automotive HVAC systems are so complicated! Wow, you should see my '77 Toyota FJ40.
Depends upon the car, my '03 Vauxhall Agila A is also primitive compared to this. There's not even an evaporator temperature sensor, because the variable compressor does everything on its own so that the evaporator never freezes, and another nice feature is that the evaporator will only get cold enough to provide comfortable air depending upon the weather. No electronics at all here, just a cleverly engineered compressor control valve. Too cold? Rotate the heater knob a bit until comfortable.
Very informative video 👍
Thanks
awesome education. Thank you regards
Very good video.thanks.
You are welcome
Perfect explanation!
Thank you
Thx you for making a cool video it explains throughly.
Back to u bro. After my vecation.(kuwait---India)
Thanks from Canada
Thanks for the video! Could you someday disassemble some high pressure diesel injectors or a high pressure supply pump? Just giving some ideas.
Thanks for the idea...if I get my hands on a diesel, sure!
Great Video.
Thanks
Very good tutorial! 😎
perfect explanation
Great informative channel. In my 2019 Nissan Patrol Y61 the AC is very cold when car is moving but when I parked & engine is on AC become warmer. Well can you tell any suggestions to make it constantly cold.
يهمني نوع السيارة التي في العرض
هل تعرفها
وشكرا لك
انفنيتي G35
Thanks. I find many car AC systems are like that, more RPM means more energy for the system to cool down since it does suck alot of energy off the engine
We love your videos for going through dissecting the components and explaining the theory and operation. You have all the ingredients to be a good teacher and a mechanic. But can you make a video longer and explaining troubleshooting. We love to watch your videos and don't squeeze everything in 15 to 20 minute frame. I watched all your video and if you can slow and do more explanation. Specifically video on transmission and torque converter. If you can make two versions of the same video one for the ones who want to refresh and one for us who want more explanation and never opened dash board of a car. I will me watching your videos when I open mine Thanks
Thanks for the compliment. Great suggestion but the audience here wants information and fast without wasting time. That's why I edit to be as short and to the point as possible.
Any longer and I might as well open a university haha 🤣
can you do a video on extensive CAN training in layman's terms please. sounds like you know your stuff!!
I sure would be looking forward to that but I need to do some research to master it myself first!
Awesome video!
Thanks
Awesome job!
Thanks
you sir deserve 5M subs.
Can you help me get there? 😁
Thank you for making this video
9:14 that's the TXV mounted on my European MPV (tried to find a scrap one to no avail, and the original one is like 130 bucks at the dealer) and in your video i'm able to notice some nicks on the valve seat, am i right? Also, in my channel i disassemble another one made by TGK, and there are no nicks on the seat, but, even though the ball is able to seat completely, the valve still never closes even if i completely adjust that little plastic nut to the closed position and then freeze the power head (that's a "cross charged" valve and you find it with variable displacement compressors and rotary compressors, i can link some patents that show how these ones work; on scroll and vane compressors, they apparently help to keep the evaporator from freezing by keeping a little flow of liquid so to prevent the suction pressure from going down too much; on variable displacement compressors, they keep the control valve from malfunctioning and also keep the compressor lubed; the nicks on the valve seat may actually do the same thing)... also, in the TXV i disassembled, the ball is attached to the metering rod... anyway, thanks for disassembling it!
I didn't pay attention to any nick's in the valve seat but that would be an interesting way to let things be lubricated.
This system had way too much green dye
@@speedkar99 Yes, it also keeps things lubricated even when the evaporator is cold and the TXV is closed (practically speaking). Rear seat evaporators, for example, have nicked seat TXVs so that the oil doesn't pool right behind the TXV when AC is on but the rear blower is kept off. Unfortunately, TXVs that stay open, either because they're cross charged or nicked, also allow liquid refrigerant to migrate to the compressor while the system is off, causing a lot of noise (scroll, through vane, that sometimes start up noisily for this reason) and performance (variable displacement piston compressors, that sometimes take a little more time to go into full displacement than usual) issues...
New sub here great explanation
Thanks for subscribing
Great vid!! keep it up. thanks
You are welcome
Love your videos speedkar99, I have learned how to take better care of my car.
Glad you enjoyed it
nice video, btw is there anything stopping air escaping from the evaporator drain, when there's water dripping it doesn't look or feel like there is of any forced air coming out? But then lots of people clean their ac by putting foaming cleaners through the drain hose.
That's a good question, I didn't see to disconnect the hose to see if there is a valve
Good question, i guess the blower fan and evaporator box is designed to take it into account so that any airflow loss is minimal and some air actually helps the condensate water drain away. I confirm there's no valve on mine, but the drain hose is still pretty narrow, and it's shaped not unlike the trapway of a siphonic toilet bowl. I've never put a finger on it with the blower on by the way
Thank you! This video is amazing!
You are welcome
Well explained Ta
Much respe man, thanks for sharin man good luck man
I really thank you
Can you teach us how does ESP System works thanks
Wow .. great as allwayes
Thanks
0:48 I think that's the LoJack device installed into inaccessible area!
U r insane... What a veteran. !!
Thanks
the green "stuff" supposed to be a leak detection agent. So this system had leeks prior and someone used the liquid to see (with UV) where it leaks ...
Yes
Amazing videos
Where do you get the drawings from ? Are they from the manufacturer ?
lot of moving and load bearing parts in plastic... how was the reliability on this model?
I wouldn't call the plastic load bearing. Usually the doors are the first to break off or get stuck, or an actuator fails
Just wonder how many days took you ensamble and dissemble that mechanisms
great video
So nice video
Sir I am Eric Ang from the Philippines. I have a Mitsubishi Mirage G4 2018 model. The AC runs under an HVAC SYSTEM. Old school AC we put thermostat on half cold level so as to prolong the life of the compressor and for fuel efficiency or save on gas. For the HVAC SYSTEM is it true that it is the other way around? I mean is it true that if you want to save on gas and not keep the compressor always pumping, it is more beneficial to set the thermostat on full cold? , so as not to blend the cold gas from the evsporator with the hot air from the heater core? Pls enlighten me if this is true or a myth. Thanks and more power.
Myth. The most important thing is to always maintain enough refrigerant charge to allow enough oil to return to the compressor at all times. And to ensure the condenser is able to reject enough heat (fans, air dams must work correctly and condenser fins must be kept clean; a fan motor or fan clutch can be bad and spinning the fan way slower than intended even when it isn't making strange noises) to ensure a good enough compression ratio. All compressors, even ones never ever mistreated, do wear eventually. Want to keep the evaporator cold enough? Run blower at low speed. But the more the clutch cycles in order to prevent the evaporator from freezing up (keep in mind that automotive expansion valves are already calibrated to stop the evaporator pressure from dropping down too fast and therefore the evaporator fin temperature from reaching freezing temperatures too fast, by means of a cross charge that prevents the evaporator from starving at low evaporator pressures), the more the clutch wears.
Valuable information
Perfect explanation as always. Would like to ask just one simple question: How does the system work to minimize the compressor usage (or power consumption from the engine) when you select a higher temperature as it uses a mixer and not an on/off principle? Or it doesn't? Thank you!
I'll try to answer. Since the car's compressor displacement is externally regulated by means of electronic control, the control valve solenoid on the compressor will be actuated so to keep a higher suction pressure and the compressor will reduce its displacement earlier as a result, keeping the evaporator warmer. If the compressor control valve is of the internally controlled mechanical type instead, a lower discharge pressure will act upon the valve's evacuated bellows (due to the lower ambient temperatures) and they will be able to expand earlier, achieving the same exact result, that is, a warmer evaporator and less power required to turn the compressor on average.
@@teravolt6113 Thank you for your answer (sorry for the late feedback).
oh and by the way , YOU ARE AWSOME!
I sure am thanks
7:26 That’s how I approach pretty much every work order
Great video, are the block expansion valves adjustable like in your video to allow more liquid to flow into evap? Trying to lower the vent temp to 40° from 45°.
That little nut controls how much the evaporator fills up with refrigerant indeed, but i highly suggest you to never touch it or you may damage the compressor (i.e. if you open it too much you may slug it with too much liquid, or if you close it down too much you may deprive it of cooling and lubricant). If you feel the TXV has some issues, just fit a new one. By the way, the TXV will never control the evaporator temperature. It will only control at which temperature the refrigerant will exit the evaporator and this is meant to prevent it from exiting the evaporator's outlet as a liquid, even though, with this valve, the superheat will progressively switch to 0 as the evaporator cools down, and as a result some liquid refrigerant will start leaving the evaporator (this is meant to keep the evaporator pressure from dropping down too fast, avoid interfering with compressor control valves and keep the compressor lubed). The minimum evaporator temperature is controlled either by a pressure switch, an evaporator temperature sensor or a compressor control valve. What you have in mind will, at most, control how fast the evaporator becomes cold, but again, don't touch it. Look elsewhere to solve your problem.
I would assume the needle spring will weaken over 10 years or some of the gas leak out of the temp sensor disc. A weaker spring would allow the needle to open more allowing more liquid and faulty disc would not push needle down enough, I would say the later is more likely to happen. TXV are very cheap and if I gain 5° more cooling its worth it, only negative is system needs to be discharged.
@@metalhalide4043 The power charge will never leak out of the disc, it's a tiny amount, there's also some adsorbent so that the valve won't "hunt" superheat. I obtained a 20 year old one i like to play with, i've disassembled and reassembled and tested it again and again, and it opens and closes perfectly. On my channel i show how the ball closes the valve when you spray liquid canned air upon the disc... never seats fully closed though, because it came from a car equipped with a Sanden SD6V12 variable compressor...
Good info thanks
@@metalhalide4043 TXV systems never cycle on suction pressure that i know. Only CCOT systems do that. TXV systems only cycle on the output of a evaporator temperature sensor, if the compressor is of the cycling clutch type. With a fixed displacement compressor, very low suction and high/normal discharge means stuck closed TXV, normal/low discharge and high suction means stuck open TXV. With a variable displacement compressor (for example Harrison V5, Sanden SD6V12), pressures won't tell you much because the compressor is able to adjust working pressures. Noise is more of help, loud groaning noise means low displacement operation and this tells you of a compressor that is trying to increase a very low suction pressure (created by a stuck TXV for example) by fully destroking. Stuck open TXV is instead indicated by frost on the suction pipe. Then there are externally controlled compressors. A lot depends upon the compressor...
Can the car's evaporator core be installed in a home air conditioner?
Thanks for sharing bro. Allah bless u
Welcome
You are great..
I sure am
If compressor is engaged but no difference in High and Low side pressures, could it mean that the TXV is stuck wide open?
Hi speedkar99, if the heater knob is not on (ie temp set the coldest), does coolant still go through the heater core?
Yes, but on some vehicles there's a bypass valve
@@speedkar99 Thanks. So if there is a bypass valve, there won't be coolant going through? Mine is a Camry, I touch the pipe that's going to the heater core in the engine bay, it seems hot.
What year and model is your GS? Any oil consumption issue?
2007 GS350 RWD. Burns a little but not enough to top off between oil changes. 265Km
Very good
I've always been wondering - when you turn the HVAC off what happens to the coolant in the heater core? Does the coolant still flow through the heater core basically making it super hot, or are there some bypass valves to redirect the flow around the heater core to prevent all the plastic in the air mixer from overheating?
Some vehicles have a coolant shut off valve outside the firewall that blocks the flow of coolant thru the heater core. This one doesn't appear to have it.
I don't think the heater core can get hot enough to melt the plastic housings
@@speedkar99 ah, ok. Thanks! I noticed in my car (regular HVAC controls with knobs, no climate control) when I turn the vent selector to 0 I still get a little bit of hot air coming from the dash vents. I would assume that means that there's no coolant shut off valve in my car.
Anyway, thanks for another great video! Straight to the point as always. And I absolutely love your toothbrush pointer haha.
In my Vauxhall Agila A there's no heater flow valve. Water is always going through it. The heater flap takes care of everything and in the summer, when the heater knob (directly connected to the heater flap through a Bowden cable) is on the cold position, i still get ice cold air at the vents even when coolant is hot. Also, running AC also seems to unstick the distribution flaps in the heater box, which tend to stick whenever i've left the car in the sun for a long time.
Nice bro.... 😙
Best coach