Automotive AC Diagnostics, Operation and Repair

[@JeffLifeInReview]

This is probably one of the best AC videos on youtube. This guy breaks every aspect of the system down, how it should work, things to check and expected outcomes and possible issues. We even got to watch him diagnose a vehicle. Wow this was great and more people should be subscribing to this guy. I feel like I just got trained like a mechanic!

[@ecstaticpenguin768]

I'm here for the second time.

[@ajsnowskis]

Best auto AC video on KZbin. A tech that actually knows how the AC system operates and explains each scenario so you can use your own brain to determine your problem. THANK YOU!

[@TheMrChaddles]

I love the fact that you didn’t edit out the part where you diagnosed that it was the hot/cold control knob... I like the humbleness and your sense of humor as well

[@Machewching]

Because of your videos, I was able to go from no AC experience to successfully completing a complete AC overhaul on my beloved 95 chevy g20 conversion van, which has front and rear AC. I replaced the compressor, pressure switchs, evaporator, orrifice tube, expansion valve, o-rings, flushed everything, vacuumed, and recharged. I learned the hardway that Santech is not better than Acdelco, and your diagnosing methodology came out in me and I was able to use the gm service manual to deduce that my recent ac issue was due to a bad high pressure switch that I installed new during the overhaul of last summer. Well ysterday I completed and it is working correctly now, so I thank you R&W!!

[@arolon9173]

I actually enjoyed the explanation. Normally I just skip through the Blah, blah, blah but your mixture of humor and knowledge is outstanding. Keep up the GREAT work!!!

[@yutao1982]

This is one of the best AC videos on youtube!

[@flyboy2610]

Great video! One thing I would add: With the style of AC gauge fittings you have, watch your gauges as you screw in the knob to open the Schrader valve in the service ports. As SOON as you see pressure register on the gauge, STOP! Far too many people screw those knobs down all the way and damage the Schrader valves. Then they won't seal correctly and all the refrigerant is lost. Seen it happen too many times.

[@donaldnealious9662]

Nice video. As an electronics tech with 40+ years experience, I loved your explanations, with visual aids.Your outcome was real world.

[@ferndog1461]

The only video I found that explains the proper valve use. When just measuring pressures, the two valves are closed. When vacuuming the system or feeding Freon, open appropriate valve. Thanks! People, please buy this tech a coffee. Peace.

[@maryanndemko]

As usual, awesome explaination. I am a very very small used car dealer (and female) and really appreciate your tutorials because otherwise I could not make it in this economy. Thank you SO MUCH!

[@wesvohnoutka625]

This is THE BEST video out there. He explains himself very well. You will want to save this video for future references.

[@dave.s62]

I realize that this video is old, but it is one of the best car repair videos I've seen. The on-air guy helps with diagnostics and repair. There are a lot of repair videos out on youtube (and that is great), the issue for us do-it-yourself people is the diagnostics. Great video!

[@WavingWorld]

Smart, thorough, snappy, AND hilarious???? What a great mechanic

[@jeffgilbert147]

This guy is a real mechanic. Very well done.

[@victorp7555]

That was the most fulfilling outcome for education. You go past the physical refrigerant system and diagnose electronics. That’s what it takes sometimes thank you for that surprise

[@ctscantechnologist]

And the evaporator core is usually in some God forsaken place in your dash. 😆

[@benkanobe7500]

You are crazy smart and very humble. Thanks for this very honest you tube.

[@johnhogan2370]

I can’t unhear how he says ayseesyssem

[@puffnstuff12]

Thank you for taking the time to make this video and for your detailed explanation of how the system works. I had to open my system for the first time on Tuesday to replace my compressor, orifice and accumulator at which point I discovered that the orifice was installed backwards.

[@watermanone7567]

Very good video. I have done refrigeration for over 59 yrs. and this video is one of the best explanations of how the systems work. Thanks

[@chrisgarcia3198]

Great job in explaining. You were technically correct explaining how the low pressure switch has an open or closed connection to pass electricity. Very good explaining technical in simple dialogue. That is what makes you a technical teacher! thanks for your time and effort! Keep up the good work. 👍

[@davidfisher535]

Would have recommended unhooking heater hoses from heater core for a cheap work around for summer. At least the owner could get some a/c. Would rather be cold than hot any day.

[@charlies6546]

@@davidfisher535 better yet, clamp them bad boys n ur done...

[@MontyFly]

2 years later I have a car with your 3rd example with a high side over 100 psi. Now I at least have it narrowed down to an expansion valve stuck open the evap intake or a check valve in the compressor. Thank you for your very helpful video.

[@pmolczan]

He did all this leg work and chasing down the problem. Got paid ZERO for all that. Much respect to good mechanics 🧰

[@elsabiopr]

SUPERB, you explained it as teaching a 5th grader. BEST instructional video

[@alaskamike3577]

I think you did an excellent job of explaining the pressures and why the system reacts the way it does. Nice to add a little humor. All in all, very helpful. Much thanks.

[@luisloks]

HEY GUYS, for those of you that have a similar issue, you can always just break off the blend door from its controller and use some tape to close it for ac for the summer months so that you can have cold ac without having to take the whole dash out and replace it . just fyi. I did this to a 97 ranger and its been working great, just rig it using some gray plastic tape.

[@bigtruckacman]

or you could just bypass the heater core.

[@haroldclark4485]

I hope you are a teacher at a high school or heading there. I have watched at least four other videos on this subject, some twice. While all the info was mainly there, none had the clear delivery of the essentials like yours. Great!

[@Jursaw]

I learned a lot from this video compared to many other auto A/C videos

[@maxxmasson4263]

I agree with you ,I feel the same way ,excellent coment

[@kanukster]

Me to...and 'Chico' was funny!

[@wajarasemmanuel5935]

Jursaw thank you so much

[@ljose007]

Same here

[@jimmysapien9961]

He explained very simple 👍🏻👍🏻👍🏻

[@travisbennett8909]

Hands down, the best AC videos in existence. You have true knowledge and understanding of this system. You should think about teaching / instructing.

[@oljames1687]

..Very Good Explanation of how the AC System works and How to Diagnose it !!! You did a Better job than most of the so-called "pros" on KZbin! This is a handy video because it helped me find out that a pressure switch is bad on a '94 Crown Vic. Thanks...!!!

[@1ManNamedDan]

I'm jelly of your Vic bruh. Tried to buy a police interceptor but somehow ended up with a Jetta - It's black - and Sacramento triple digit summers with no AC in a black car is a ticket to roadside cremation.

[@michaelm7874]

This is a great channel to follow. Too many bs mechanic channels getting into "don't buy this or that, never put this on your car, share your ride and etc". This is pure educational, great explanations on everything

[@qualityrenov]

the best tutorial ever on the subject. I thank you for taking the time to post this Sir.

[@mfslyphantom8811]

The evaporator is “in some god forsaken place in your dash” lol! Trust me this guy has been there done that as it is a very accurate way to describe what it’s like replacing either a evaporator or a heater core on any vehicle made in the last 50 years.

[@deanhaidar5894]

I really learned a lot about how AC systems work and how to diagnose the entire system, keep up the good work and thank you!!

[@jimmysapien9961]

Very interesting 👍🏻

[@defyanse]

Excellent! I've watched quite a few ac troubleshooting videos in an attempt to solve my ac issues. None have been as clear or comprehensive. Thank you!

[@jbj27406]

Very excellent, instructive video. I had a similar problem once before. In the hot months I would physically turn off the hot water supply from the engine cooling system with a manual valve, or simply disconnect the heater hoses and bypass the hvac system. Of course, it's a little inconvenient, and you have to reconnect to turn the hot water back on in the cool or cold weather.

[@oculophilia8724]

This person is the true g. The solution is always in the comments.

[@TD16V]

This is probably the best video I’ve found, that succinctly describes correct operation and possible faults by the gauge readings… Thanks!

[@mrmohr2]

I loved your lemonade comment at the end! Plus I learned a bit about how to use the gauges, and how to diagnose problems. As always, you do a fantastic job editing your videos.

[@jimmysapien9961]

Exactly

[@michellemartel7496]

I love how you explain the diagnostic process alongside explaining the engineering! The problem I have wasn't addressed in this video and yet I'm still glad I spent my time watching it. Thank you for the education!

[@yaiqaab]

You are a very good teacher, kudos very informative, very professional, very excellent. One of the best videos I've seen yet!!!!

[@firstmkb]

Not a bad ending for a video, just for the guy with hot air. Very good walk through of the system!

[@jimnoyb1209]

You are a very sharp tech and very entertaining teacher, I love that pry bar pointer you use. Thanks.

[@SwedishHunter77]

Very technical detailing explanation in HVAC system. I gratuated in HVAC school and they barely explained like this professional way. I am consent and positive with you.

[@LesSummer]

You are on your way to great awards. This was SOOO helpful. Thank you! Keep up the awesome work!!!

[@johncaufield760]

A really good explanation of the car's AC and the faults that can occur.

[@nandi2685]

Awesome video, yet again! My knowledge of cars has come a long way thanks to you. Always informative! Bless you man and thanks for helping the DIY community.

[@TheMagoramirez]

Very helpful tip, I’m an HVAC Technician for industrial and comercial bldg’s but I have never even thought of look into cars a/c.

[@ryanellison7250]

Most comprehensive and well explained AC tutorial I’ve ever seen. Very thorough and great info. Thanks so much!

[@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...

[@katharinelewis1]

This is the most helpful video I've watched in a long time! Youre a great teacher. Subbed

[@Mnewkirk76]

Learned more from this video than I have in mechanics class. Thanks for sharing your knowledge

[@etripp111]

Great explanation as to how the a/c system functions. Thanks for the overview which makes diagnosing a/c issues easier.

[@platinummind1697]

You know your stuff, and you know how to clearly explain it. That's talent! You should be a collage professor. New subscriber here.

[@jimmysapien9961]

He is 😀

[@juanrrobledo89]

Good presentation and great job with the diagram and explain the details and possible scenarios that do occur, thanks

[@andrewribner3474]

I'm a subscriber to your channel and I have to tell you, when I see you've posted something explaining how an automotive system works I know it's going to be something I won't be able to just sit back and give a leisurely watch to. Rather, I know it's going to be something I'll have to give some real attention to. I do that because I know that if I do, I'm going to have something explained to me by a truly talented teacher. Thanks for putting "it" out there for me to "get"". You've a great gift.

[@gtothepowerof6]

You did a great job walking through the system. Awesome video.

[@faustogonzalez8397]

Great job, I have watched numerous videos explaining the automotive A/C cycle, 1st time it was mentioned that the actual on/off cycle of the compressor is controlled by the low pressure switch. Makes sense, a pressure too low the designed spec of the compressor could damage it and therefore shuts off the 12 v feed to the compressor coil clutch. Keep up the great work!!

[@bigtruckacman]

On this particular system that is correct., sorta. The switch he described is actually a Cycling Switch not a low pressure switch. It has a range usually between 22-44 Psi. where the compressor will cycle. Other systems, mostly expansion valve types will use a thermostatic switch to prevent freeze up of the evaporator core and a low pressure switch to prevent compressor damage in the event of refrigerant loss. International trucks use temperature thermistors to sense the inlet and outlet refrigerant temperature at the evaporator and a high side pressure transducer to actuate the engine fan and turn off the compressor in the case of over pressurization. This is all controlled by the ESC body Controller ECM. I give these examples not to confuse you but to show that A/C systems are controlled differently depending on how they're engineered.

[@jimmysapien9961]

Ron Sposato that’s Mind Blowing 🤔 wow Thanks for Sharing 👍🏻

[@jamester000]

pahaha the ending lemonade quote was so unexpected and hilarious LOL

[@ckochenower]

Skills! Thank you for sharing. Very clear and concise root cause analysis. It would be great to have a series of these videos with different root causes and labeled with the root cause so the viewer could watch and follow based on the readings/results they are getting.

[@claudiosantana2019]

good stuff, quality content went over whole ac system explaining clearly.

[@DELREYGUY]

I have been working on cars for many years... Every time I see one your videos, I learn something new.. You are a very good mechanic, and do great videos, in well presented formats for all levels of viewers.. Awesome.....👍

[@davidachten1162]

Mr. R NW, you are a genius.

[@bobbyk6585]

Wow, an actual mechanic who troubleshoots and tests. Impressive work my friend.

[@malfaro4]

I definitely took a lot of notes..Excellent job sir.

[@timothy2830]

Your 'Serviced Port Pressure' chart is so correct! Thank you for including it in your video. Google "AC Pressure Chart" and you get one from A/C Pro that has everything too high. When I used their chart, I got diminishing returns and my AC compressor would hard start like it was swimming in liquid. I used your chart and my car is now blowing a cold 40F on a 90F night (I'm in the desert) THANKS SO MUCH!!!

[@humbledhands]

I was comparing his chart and thinking he has the wrong one because it does not say r134a on it? What kind of car do you have? Just wondering what refrigerant you use?

[@timothy2830]

@@humbledhands r134

[@pauldavis5075]

Bypass the heater core, top off the AC it's Southern California you don't need no stinkin heater!

[@booyakashaboy7250]

I was about to suggest the same thing. Its cali. Screw the heater! Jam glue or jerryrig that things to full blast cold! I'm sure the owner'd prefer that over the blazing heat he's been enduring these past few years. Too cold? Open a window or just turn it off. 😎

[@zuranku]

@Holy Drug Lord🔼 That's right!!! I retain my heater core for those few weeks of the year where the temperature just DROPS all the way to sub 65 degrees!!! Heater goes on FULL BLAST!!!

[@bryanelliott1928]

That's a really good point 👌

[@EverydayProjects]

That quote near the end is Spot-On. Well done! Great video, as always. Long-time subscriber here.

[@Candoit2]

Thanks! Great video and you sound very knowledgeable about AC auto systems!!

[@yorkcat1973]

@Ratchets And Wrenches I almost forgot to say "good video it was very informative, clear and helpful. Thank you".

[@creepycrawler43]

Thank you so much for doing this video! Awesome man now I feel confident that I can fix my AC

[@devin30thirty]

I like videos like this. Humble demeanor, easy to understand, and funny as hell. Good tutorial and I'll be checking out your other videos.

[@NorthWoodsVideo]

Good presentation and your video production quality is improving over previous. Keep up the good work mate.

[@user-sh9du2nv5y]

Best A C lecture i have seen on u tube well explained in simple terms for troubleshooting.

[@ncrdisabled]

Great explaining of how it works . Please let os know if the owner wants if fixed. I also have the same meter you have got it from harbor freight . I only paid 15.00 for it for a black friday deal. I also get the free meters when they have the coupon in the paper. But only when someone drives me there. As I spent 7 years in the NAVY on submarines during the 80s and got hurt bad leaving me in a wheelchair I have a morphine pump so I can not work but get to watch your great videos!!!!

[@elliottcole6428]

I've been waiting for a good deal like that on this gauge! Now it's about $60. Nice find! And thank you for your service, I'm sure that was some very interesting work and fun experience dealing with submarines.

[@steelriggins2101]

I am always impressed by your ability to teach a very difficult subject and I am always able to learn and I really do appreciate everything you put out there

[@2135nader]

Man you know your stuff, and also funny at the same time. thanks I learned alot

[@zachariahx1727]

Great video. People have tried to explain this to me many times but the way you explained it i finally can understand

[@patrickmorrissey2271]

Actually a really good explanation of how the AC system should work, and what your gauges are telling you. Very nice. Great video.

[@SanchoSanto]

Thanks for the detailed explanation. With each video I watch about AC I get a little more knowledge to help me figure out my pro blem and hopefully fix it.

[@MRosati5000]

Shame you could not just replace the blend door, something easy.. prob crappy design. Good job giving your info.

[@mikeburch2998]

That was a great tutorial. Pulling a dash apart is a really big deal. I plan on recording mine if I have to do it just to help eliminate missing steps during reassembly.

[@porthose2002]

Very, very helpful video. Great job putting this together. Thank you!

[@RobertMertensPhD]

Okay, finally! Nobody talks about static pressure. They all hook up the gauges and start the car. But if you have a leak (no coolant), the A/C won't turn on. I had zero static pressure on both gauges. This tells me a have a hard leak. Thanks for that little bit on static pressure. Now I just need to know where to get some of that dye and a UV light. Oh, and yes, this is Florida. It's February, and surprisingly hot this year.

[@DA-zi6eq]

....Make lemonade 🤣🤣 man not only you great at explaining, great sense of humor too.. keep up the great work.

[@theworldisavampire5938]

Thank you, man! This is the only video where I learned when is the correct time to read the gauges to be compared to the chart. Every other video says this much of pressure readings but the needle is moving all the time and doesn't mention at which point those readings should be taken.

[@lauragreen7887]

"...Usually in some God-forsaken place under your dash" 🤣

[@baderhaddad5728]

Laura Green lol

[@eddieg329]

@@jimmymcknight4563 It be Nice to hear YOU try speaking Spanish with out an accent .. Just saying .. or even TRY writing it ..

[@bobebstein7779]

Eddie G I agree Eddie. Maybe jimmy will make us a video to his liking.

[@clarencemiles828]

@@baderhaddad5728 mzmmzmmmmmmmmmmmmmmmmmmmmmmmmm

[@clarencemiles828]

@@baderhaddad5728 m?z-mmmmmmmmmmmmfmm

[@TheNickowen08]

What I thought was the worst case scenario isn't the worst case anymore. Excellent video. Thanks for taking your time to make this video.

[@richardnoel3141]

Thanks. This is really helpful. You explain it really well!👌🏻👍💯

[@MrROTD]

In a hot area of the world a good AC tech must be gold, theres only two really hot months where I live and I can't live without it , it would be like having no heater haha

[@deespasojevic3013]

Great job 👍👏 big dunk contest ups to you! You're a awesome teacher

[@kermitefrog64]

Excellent video. By the way I believe the saying you shared at the end is, "When life gives you lemons make lemonade."

[@plsmoothy]

I watch a lot of auto repair guys on KZbin and I have to say your content is right up there with the best of them. Good work man. Keep it up!

[@jhuff692]

I've been wanting to find out exactly how the all-electronic climate controls work. Thanks!!!

[@eduardovalenzuela6991]

Great video. You explain perfectly. I’m a caveman, and I understood. Thanks

[@jimmysapien9961]

Haaaaa

[@minervamondelus3692]

Perfect i like all exercices ....

[@saulgarcia5114]

Great video. I have just gotten into teaching AC at my local college and this video answers so many questions and helps so much. Thank you!

[@TheDervMan]

Excellent, and funny video! Thanks for sharing. 👍🏻

[@AlAl-wu7mp]

Excellent video I leaned more today than the 100's of books I read on AC before this.

[@yao2071]

Thanks a lot bro!!! Really helpful!

[@MrGoThrough]

this guy should get more subscriber..cmon..good job in explaining and sharing with us the knowledge.

[@tawidave7092]

"You can't always get what you want, but if you try sometimes, you can make lemonade with it" - philosopher Hahahahahaha!!!

[@deasttn]

Yes, you get that indeed!

[@briantickell7942]

Tawi Dave This Guy was funny as hell. I’m going to have to watch more of his videos. 😂😂😂

[@robbyramlal5747]

an original wise saying from professor RnW

[@malimag99]

Thank you for your detail explanation. I do have a better understanding now as a DIY on how to troubleshoot the ac system. You guys make the world a better place by sharing you knowledge with the rest of the world.Great job my friend.