Automotive AC Diagnostics, Operation and Repair

In this video I am going to show you how an Automotive AC system works, how you can diagnose issues with it using an AC manifold Gauge Set and how you can repair it.
Here are links to products which were used in this video:
AC Manifold Gauge Set: amzn.to/2sjxNux
Test Light: amzn.to/2sjrVSa
Multimeter: amzn.to/2r9PKaJ
Aligator Wires: amzn.to/2se6zVB
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Disclaimer:
Due to factors beyond the control of Ratchets and Wrenches, it cannot guarantee against unauthorized modifications of this information, or improper use of this information. Ratchets and Wrenches assumes no liability for any property or personal damage that may arise from doing a repair on your vehicle after watching any of my repair video's. Due to factors beyond the control of Ratchets and Wrenches, no information contained in this video shall create any express or implied warranty or guarantee of any particular result. Again Any injury, damage or loss that may result from improper use of tools, equipment, or the information contained in this video is the sole responsibility of the user and not Ratchets and Wrenches.

[@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.

[@jeffgilbert147]

This guy is a real mechanic. Very well done.

[@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

[@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.

[@benkanobe7500]

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

[@johnhogan2370]

I can’t unhear how he says ayseesyssem

[@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!!

[@davidschwalbe9309]

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!

[@donaldnealious9662]

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

[@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...

[@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!

[@yutao1982]

This is one of the best AC videos on youtube!

[@elsabiopr]

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

[@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 👍🏻👍🏻👍🏻

[@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.

[@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.

[@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.

[@qualityrenov]

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

[@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!

[@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.

[@LesSummer]

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

[@etripp111]

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

[@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

[@mmperez1911]

Just did my entire ac replacement..thank you for time in making this video!

[@yaiqaab]

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

[@gtothepowerof6]

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

[@TD16V]

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

[@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 👍🏻

[@claudiosantana2019]

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

[@katharinelewis1]

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

[@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.

[@jhuff692]

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

[@jimnoyb1209]

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

[@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

[@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.

[@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

[@ryanellison7250]

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

[@CBx91]

YES!!! Finally found this video again. I've been looking for it for days. Thank you for taking the time to explain how the system functions and what different gauge readings could mean.

[@bobbyk6585]

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

[@TheDervMan]

Excellent, and funny video! 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.

[@pedrogadea4926]

I'm impressed, great video. Very clearly explained, you know your stuff.

[@Candoit2]

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

[@davidachten1162]

Mr. R NW, you are a genius.

[@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!

[@thestatesman7405]

I felt like I was in my favorite class learning my favorite topic..Good job bro

[@richardnoel3141]

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

[@creepycrawler43]

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

[@wesvohnoutka625]

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

[@lukewalker4089]

One of the more thorough diagnostics I've seen, thank you!

[@malfaro4]

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

[@juanrrobledo89]

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

[@fridaythe13thpartx]

Great video.Really helpful and explained in a way that is easy to understand how the system works.Gonna be tackling my AC problem with actual knowledge and understanding now!

[@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!

[@porthose2002]

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

[@DA-zi6eq]

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

[@bigfatlazydork]

This is the best A/C troubleshooting and theory video I’ve seen. Kudos for helping me to figure out what’s up with my A/C system 👍👍

[@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.....👍

[@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.

[@deespasojevic3013]

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

[@girohead]

Very good and thorough instruction, even if one has someone else do the repair, they should understand the system. I don't know how often I hear people with used cars need 'new compressor', etc. I see now that more likely they had a valve or other issue. Keep up the good work!

[@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.

[@2135nader]

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

[@patrickmorrissey2271]

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

[@emwrmi]

AWESOME STUFF by a well structured guy who obviously knows what he is talking about. Great!

[@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.

[@yao2071]

Thanks a lot bro!!! Really helpful!

[@NorthWoodsVideo]

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

[@pervezmahmud5805]

Very thorough explanation like a pro. Understood every word you explained in 16:47 mins. Diagram with low and hi pressure 👍 you got my subscription and 🔔 rings

[@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.

[@JoeBakerOutsideTheBox]

Nice tutorial, new subscriber

[@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.

[@christen1075]

Well done, well explained, and very relevant to the Ford Escape I'm trying to learn how to fix...just for the fun of accomplishing something "self taught". Never fail to learn something on your videos.

[@jerrvang7339]

Perfect explanation to fix AC. Wow. I understood everything. Just amazed with the instructions 👏👏👏

[@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!

[@eduardovalenzuela6991]

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

[@jimmysapien9961]

Haaaaa

[@minervamondelus3692]

Perfect i like all exercices ....

[@monfoxtrot3123]

this was very informative! Thank you very much! I'll be replacing my a.c. compressor and the low pressure hose in the near future.

[@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.

[@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

[@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.

[@roberthayes5037]

Thanks for such a well explained video. You do explain with detail. I was able to get my ac cooling down to 40 degrees. Thanks again.

[@daisy8luke]

Great vid , brother. Having trouble with my Tacoma ac. This helped me tremendously!

[@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 👌

[@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.

[@Mnewkirk76]

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

[@Guywithcrazyideas]

This guy is super smart.

[@Max-wy2dl]

Disconnect the heater core hoses so you dont get heat

[@MrGoThrough]

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

[@dwaynemadsen964]

Quick and to the point(s) (because you covered a LOT of material) Well illustrated, a range of examples of findings and what they most likely mean. Dude, are you a College Professor moonlighting as a mechanic? AWEsome job. Thank you, good sir.

[@kenqv3481]

location of evaporator "Some God forsaken place"- got That right.

[@travisthompson3700]

Very True

[@roadworthy6901]

Seems complicated, a lot of components that can fail and cause your cars A/C not to work, I always found it extremely funny from my experience working at an auto parts store on how many people think those freon cans will simply fix their A/C system! LOL

[@velosocardona5310]

My nissan exalta two thousan model aircon blower fun wont shot off can you help me how to fix it my self

[@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!

[@maxwolthuis]

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

[@cleatrampler]

Bypass the heater core, that's what we do in south Florida. Heat is worthless here as it is only a waste product to get rid of.

[@yaiqaab]

cleatrampler, I was going to ask the same question.

[@hanskinslo326]

Up north, this is not acceptable, of course.

[@wholeNwon]

Dumb question: Why don't you just block the heater hose? If still no cold air, then the blend door has failed in the heat only position rather than somewhere in between. If so, perhaps the door can be moved with a borescope.