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!

[@yutao1982]

This is one of the best AC videos on youtube!

[@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!!

[@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

[@ctscantechnologist]

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

[@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!!!

[@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.

[@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.

[@jeffgilbert147]

This guy is a real mechanic. Very well done.

[@wesvohnoutka625]

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

[@donaldnealious9662]

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

[@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!

[@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!

[@WavingWorld]

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

[@benkanobe7500]

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

[@johnhogan2370]

I can’t unhear how he says ayseesyssem

[@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

[@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.

[@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

[@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 👍🏻👍🏻👍🏻

[@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!

[@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

[@travisbennett8909]

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

[@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 👍🏻

[@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

[@qualityrenov]

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

[@EverydayProjects]

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

[@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.

[@LesSummer]

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

[@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.

[@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

[@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.

[@johnsmith-dm2tq]

i have a unique issue and was hoping for some input, i have a mazda 6 2015 and it wont stop blowing cold air. it has dual air and heat if that matters. if i set the temp at 65 its awesome and plenty cool however if i turn off the ac button and set the nobs at 85 it mixes hot and cold and just blows warm air...i am stumped on where to begin.

[@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.

[@johncaufield760]

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

[@yaiqaab]

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

[@TD16V]

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

[@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.

[@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...

[@jimnoyb1209]

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

[@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!

[@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.

[@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.

[@katharinelewis1]

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

[@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!

[@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.

[@etripp111]

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

[@johnelmore2459]

Great Instructions for troubleshooting the ac system. With regard to the blend door, it is very time consuming to change if you use standard procedures. I had the same failure. My approach was to cut the floor out of the blend door box and replace it from below. 2 hours to complete. I made a new floor out of clear acrylic sheet and relocated the pivot point for the blend door in that acrylic sheet. I attached the acrylic sheet with a series of holes and safety wire. You have to be a bit of a contortionist to get this done. Very close quarters. I made all the cuts with a dremel. Probably not something the average auto shop will do. It is a bit of a Macgyver process. By the way, the new blend door from Ford was about $28, 6 years ago. Dealership wanted more than $1000 in labor to do this. At the time, the truck was a 98 with 80K on it. You are also right with regard to this being a common failure. When you see how under engineered this blend door is, you will also understand why it is a common failure. Since I made this repair, I never turn the blend door knob all the way in either direction to insure it does not maintain too much torque on the door against the hard stops.

[@vicsamboncs]

John Elmore p

[@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

[@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.

[@davidachten1162]

Mr. R NW, you are a genius.

[@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.

[@gtothepowerof6]

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

[@dwightyarbrough]

Hey boss I got question. My compressor is cycling but 5hen cuts off and repeat. I've added a small can of 134 a and examined visually everything looks good. I got one line I believe it's low pressure line. What do I do next?

[@watchdogu.s.a.8973]

Have you been able to get your air working? What did you mean by "I got one line..."? The port that you connected your hose to for adding refrigerant is definitely the low pressure line. There is also a high pressure line that has a larger port that the connector on the refrigerant fill hose will not fit. Assuming there is a cap on that service port (which there should be... a red cap but could be black) leave it on there and *never* do anything with that service port unless you have a set of AC manifold gauges to connect. There is extreme pressure on that line. Cycling on and off is generally a sign of low refrigerant. Did adding the 12 oz. can of refrigerant help at all - does the compressor stay on a little longer between cycles? If you don't see signs of leakage from any of the AC hoses or connections you really need to put some gauges on and check the pressures before adding more refrigerant. Adding too much can damage or destroy your AC compressor so it's best to see what's going on with the entire system. Since you seem to be a do it yourselfer it might be a good investment to get a set of gauges. Harbor Freight currently has the newer version of the set he is using in this video for $64.99 although his brand is U.S. General. If you decide to get gauges you will also need a can tap that fits the line. Those are also available from Harbor Freight for $7.99.

[@NorthWoodsVideo]

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

[@marcuslauj]

The lemonade is understanding the basics and theory. Great teaching. Thank you.

[@malfaro4]

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

[@user-sh9du2nv5y]

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

[@claudiosantana2019]

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

[@maxwolthuis]

DUDE YOU ARE THE MAN!!! just answered all 12 of my questions in one vid.... you got yourself another sub my guy.

[@juanrrobledo89]

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

[@zachariahx1727]

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

[@jamester000]

pahaha the ending lemonade quote was so unexpected and hilarious LOL

[@bobbyk6585]

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

[@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 👌

[@grahambate3384]

Gr8 video mate. My compressor making noise. A/C was working good. I turn A/C on to cool motor down as radiator fans turn on(I know they come on at 109°c but I don't my motor getting that hot). Well didn't cool down, but didn't have noise. But everytime I try the noise get worst. A new compressor here in Australia $450 just to buy. Car exactly the same as a Pontiac G8 2008. 350000kns. It a pain to drive in the rain

[@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

[@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.....👍

[@Candoit2]

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

[@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.

[@creepycrawler43]

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

[@richardnoel3141]

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

[@raygsbrelcik5578]

I enjoy the detailed tutorial----Easy to follow, not difficult to grasp.

[@porthose2002]

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

[@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 😀

[@2135nader]

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

[@Mnewkirk76]

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

[@DA-zi6eq]

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

[@firstmkb]

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

[@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!

[@keithcrew2418]

Thank you for making this video, it's probably the most helpful and concise direct one I have seen yet!

[@MRosati5000]

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

[@yorkcat1973]

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

[@patrickmorrissey2271]

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

[@georgecolbert3247]

Good video. Its interesting how all the manufacturers went to plastic blend doors with servos. The old cars used metal doors with vacuum actuators and they lasted the life of the vehicle. I currently have the heater box out of my 05 Ram replacing the all the blend doors .

[@eduardovalenzuela6991]

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

[@jimmysapien9961]

Haaaaa

[@minervamondelus3692]

Perfect i like all exercices ....

[@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 👍🏻

[@deespasojevic3013]

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

[@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!

[@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.

[@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.

[@semco72057]

I am saving this video for later viewing when working on the car so I can refer back to the material in this video. I thank you for this information, and hope you are having a nice week.

[@Guywithcrazyideas]

This guy is super smart.

[@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. 👍🏻