This kind of detective work on a car is almost always fun, and it sure makes a helpful video. Nicely done. Matt, just ignore the trolls and haters. By spending so much of -your- our time responding to trolls on followup videos, you're letting them plan the agenda for future recordings. Most of us don't need to hear it, and your videos will be faster, cleaner and better.

I love when i have a issue and see you to solve it here. I just started working on my car 3 weeks ago and this is the only thing that makes sense to me Thank you!

Good job and a great video explanation. I repaired mobile a/c professional for 24 years and I have to say your thought process is right on. Thanks for the videos.

I really like how he explains how to think through what the possible problems are. It's really helpful!

Wow, I just discovered your channel. Finally someone who thinks like I do when performing automotive diagnostic procedures. Eager to watch more of your content.

Thank you so much for posting this video. I noticed last spring that my ac stopped working in my Nissan Xterra. I went a whole year thinking it was going to be an expensive fix. You helped me trouble shoot it. I first noticed the clutch was not coming on. I got my voltmeter and was about to try to chase down the issue, when i noticed that the AC compressor wasn't even plugged in. I plugged it in and BAM!! AC works perfect! I don't know if a mechanic just forgot to plug it in after doing other work on the engine, or if it was intentional. I hope it was not the latter.

Thanks for the video ! I like your attitude but I still am learning to work on my personal vehicles. I am guilty of the “replace until you find the coconut” methodology. Keep up the good work and we will keep watching and learning ❤️

Folks like you are what make this country great. I love calling it home since early 80s. I thank You 👨🏻‍🔧

Great Video man! As a refrigeration mechanic i hear "Oh it just needs a little freon" on the daily lol. Most times its just a simple electrical issue

Nice to have you back Matt and at your very best too. Looking forward to the new video on your other paid channel. Top draw as always

Thanks for showing me your isolation technique. I actually had corrosion on that plug above the clutch. Fixed now.

Brilliant. Nothing better than a logical, sensible troubleshooting procedure. Well done.

Glad to see you posting again. I miss your videos the most out of all the KZfaqrs.

Thank your man again fantastic video I love them keep up the good work you’re funny you’re awesome you’re the man thank you👀🌿🙏I learn a lot from you from watching your videos fantastical Gracias

I like your perspective on diagnostics on a automobile!

Thank you so much, my '96 Honda Accord had the 12v wire loose. I really appreciate this info!

I was like a monkey hunting around for coconuts until I found this video! 😆 15:29 Thanks so much. You probably could use a couple drinks though! Lol

You are very knowledgeable but you seem to allow the stage you're on (the internet) dictate you're delivery. Don't worry about and please stop giving into negative comments and people in general. I learned a lot from whatching this video.I had to rewind a few parts due to your "typical hack" comments. My word to you is if you are sharing knowledge do so without the bitter shade throwing. In this world no one knows it all however, all of our knowledge together can move mountains. Thanks again for the informative vídeo.

My name David from Houston,tx I just want to say thank you.... My gal Acura ac went out... I don't know much about ac system until I saw your video... My gal was panicking and about to call a mechanic...I ask her to let me check it out...It was a brown fuse... I just imagine how someone could be paying much, for something very simple... thanks

Good job man. And thanks for sharing your video. You make the fixes looking easier

I will watch every video you make sir! cant thank you enough.

Hi I just discovered your videos and they seem very informative. In my opinion you should leave the negativity out and just own what you do. By making a point of everything that people might say and will say just eats away at what could be an informative and extremely confident approach. Let the haters hate and allow us to learn from your experiences.. cheers

Good job and thanks. I am not hearing my clutch kick on in the truck. I have not yet done the visual inspection or checked for pressure. I now have a good starting point. thanks for your time.

Thanks for the add, good to watch someone do things with finess.

I’m learning and working on the electrical system is very hard for me as a headache but you make a look so easy and fun thank you very much man👀😎

Fantastic job thanks, where are the links to the other videos ?

Thankyou, very well done diagnosis.

Interesting personality. Like your tools setup. Always looking for good tools. Great way to test relay. Had the same issues so this helps. I dont do ac but cars are old and local mechanics have failed me too many times.

Schroeder's Box don't let them get you down! God bless you for all of your efforts and I really appreciate you for posting your knowledge for people like me to see so that we can help ourselves in times of desperate need. I've been on my own since 13. I've been learning watching others mostly from you tube and Google (since my papa is gone now). Your knowledge is greatly appreciated and every little bit counts. Thank you!

I gotta say... People are so freaking sensitive and they're getting free information, wtf, they should be happy for someone who is a professional giving them free information. They shouldn't be a mechanic or work in any shop, they'd be crying in a corner somewhere!

Thanks for posting the video. I am subscribed and hope to watch your other videos.

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...

Your entrance rant was hilarious

Thank you for posting this. It is going to help me trouble shoot my air conditioning on my silverado. You put it so simply i have the confidence to do this myself now. Thanks! Oh yea.... Dont let the nay sayers get to you. You got a gift , share it!!

welcome back, I missed your smart ass videos! keep up the good work hope to be watching more soon

Nicely done! I wish all problems were that easy to diagnose.

Nice work. A little common sense and the power of observation goes a long way. Good logical approach to troubleshooting on most, if not all mechanical issues, appreciate you sharing the info.

Im not kidding when I say this, my AC started blowing hot yesterday and my first thought was, damn I wish matt would put up a video. Thanks matt! Hope everything worked with the promotion

Thank you for the informative video. Really helpful

Awesome sauce! Once again, you've whipped it! Carry on...

Before the cream sits out too long... you must whip it.

15:30 you did a great job.

I am getting a truck from my in laws. It has an AC issue. Not sure what it is yet. But in either case. This was a good video on diagnosing. And I love your sarcasm. Thanks a bunch.

Good to see you again Matt, and hear you bashing Haynes manual jockeys, parts changers and visual inspectors once more!

Reminds me of.. me when I am in my shop working. I talk to myself in the same manner. Kudo;s

This is exactly how a professional mechanic shop does things, and also they hook up a computer to determine the problem, a diagnostic test is ran also

brilliant tutorial sorted my air con out. thank you

Simple to you and very hard for me. Thank you for explaining it for myself. Wonderful explanation!!!

Please answer this: So how did a wire get *cut* "while sitting at a stoplight"? Sounds and smells to me. I retired from the "repair" market years ago- for reasons of cheap, stupid people wanting free work- or trying to haggle my worth, or just plain lying to my face. I don't blame you one bit.

You should be a Radio Personality on Rock 103 FM lol you rip in to people so calm like...

Great info! blunt and to the point is exactly what this world needs now a days

Love your videos! you have fought me a lot! when are you going to do a video with steering? I have an issue with a steering torque sensor on a 2005 VW golf

I like this guy he talks the talk but he walks the walk.

I'm here to make this Video cuz I love to here myself rattle on n on .although I appreciate the help

I always enjoy your shows...correction your videos. Extremely informative and entertaining. Many times it's your sarcasm that keeps me engaged. Have learnt a lot from your content. Keep them videos comming Matt. You are doing fantastic by my Standard.

nice my ac not working watching ya video has got me motivated to fix mine as soon as i done my boll-joints thanks ya good inspiring thanks

I think your video would be much more effective by just telling us what and how you'd check and leave out all the sarcasm and criticisms of DIY'ers. We know we are amatures but like tinkering, saving money, and the feeling we've accomplished something.

Why demean others? Still I thank you for this

THE CAT LIVES! Thanks for this no nonsense, quick and dirty video! PROBABLY SAVED ME HUNDRED$

Does the computer ever use the downstream o2 sensor in vehicle to adjust A/F ratio? I'm thinking it only uses the upstream sensor since the downstream should always be a flat line with a working catalytic converter.

not just adding refrigerant but one that contains stop leak and oil. adding more oil makes evaporator heat transfer worse

surprised eric o from south main auto hasn't commented yet! or ivan

Great video, this is going to help me save money this weekend for my fix,

hi can I please have a link to you first air con diag video? I'm looking for fundamentals you refer to in the first video

Wow! Your in a very bad mood. Go get some sleep and take a shower. Geeze Love, a Hack

You forgot the first step: Verify the complaint.

I got the very same problem with a 1997chevy S10 V6 , I thank for your help , you're awesome 😇😇😇👍👍👍👍

Mate, you are a very good explainer, thanks a lot for your time.

Blair witch project quality

Your channel and content is so good but your ego is very hard to like. Thumbs up for content but you might consider it makes you look really insecure when you start mentioning other mechanics

Just had a thought. What causes the compressor to cycle? Is there a temperature sensor on the evaporator somewhere or does the compressor run until it trips the high pressure switch?

I am very interested in seeing another video like you did for understanding how the egr system works, but for the a/c. This video helped me the most with my vehicle. Thank you for doing what you do @Schrodingers Box.

I have watched some of your video before, but not this one. Some of your explanation is really help, but if you can go straight to the points and do less talk, that will be perfect.

Arrogance is definitely not a way to go young man. Check your ego. You can do things without putting others down.

Thank you very much! We followed your testing procedures, and found a loose connector on the air conditioner clutch. Just as simple as it gets. But without your video and explanations, we were totally lost. Again, much thanks!!!!!

Do you have the link to your AC video?

Great video, but do you you have to put put down other KZfaq channels and/or people that comment? Youre putting it out there, so you shouldnt expect all positive responses, man. Very arrogant......sorry

Yep, nice video, great content, and thank you for speaking to me, EXACTLY like I speak to myself when I spent a $grand throwing parts at it before I researched properly 👍👍

VERY IMPRESSED WITH YOUR LOGIC. FROM UK.

To comment on an old-ish video (but another good one!) Good info here - I hope it helps me further troubleshoot my '02 Dodge truck. The A/C didn't work when I got the truck, and I think there's more than one problem. The relay has 12v across pins 30 and 87 (load side) and also pins 85 and 86 (control side). The control side never drops to 0v when the A/C is switched on. It's ground-side switched inside the PCM, according to my FSM wiring diagram. I've verified the compressor comes on when pins 30 and 87 are jumped. While the pressure starts off in the normal range, it immediately goes extremely high when the compressor is forced on. The pressure sensor (not switch) has 3 wires - 5v ref, ground, and signal. The signal voltage is within the normal operating range per the FSM (0.45v - 5.0v). It sits at 0.7v at startup and climbs to 5v rather quickly as it follows system pressure. I'm afraid of leaving the compressor on for more than 30 seconds or so. Anyway, the switch seems to be operating. There's a LOT of green leak check in the system. I'm thinking the system is clogged somewhere. Also, I'm guessing someone tried to "jump" the sensor thinking it was a switch and fried the PCM. Next I'll use some more of your video help in verifying PCM switching. I hope I can figure that part out. Thanks for all you do.

Good point made for the visual inspection! You have a problem, as a fact, so u batter start examin the system by overruling the posible problems. Thats the only way to find t problem, everything else is a waste of time! I have a friend that does the "Visual Inspection " for ours.😄 But on the end is me that fixes all his problems. Thenks for video, it was educational!

Just found this video, and I absolutely love your approach to things. "Fix it with your brain instead of hunting around like a monkey looking for a coconut". I will be referencing this video as I hunt for my A/C issue. Thank you!

I just ran into this problem today and i am going out with my power probe to do the same thing, I did just switch the relay fuses but that didnt work so now to test the relay. Also did not check low side switch which is where my problem is coming from on the low side. I have no compressor clutch kicking in so off to check, thank you.

I am about to pay $300 to fix my ac This was so helpful. Now I know what to look for when I ask the guy to explain what was the issue was.

Good job Man that's was a good video don't listen to what they say you're just as good as the other guys out there

Luv this guy! 😂😂 Great video! 🙌🏽🍻🍻

I have also used the Devo Diagnostic Technique (DDT) as a problem solving guide for automotive issues. Nice success on the repair Matt

This is excellent. Now, just have to find my multimeter - my teenage son put it somewhere when he was cleaning the house - that was 4 months ago!

Excellent diagnosis!

Dude your so meticulous in your work great job

Matt, fun and good diagnosis, as always =D A hug from Spain my friend.

can't wait to see this!!!try to detect it...it's not too late!

MATT, good to see you back always learn some thing . cheeeeeers

Ty very much Sr. Very helpful !

I have 2000 Ford Expedition 4.6L. Idling engine in parking lot with AC running all the sudden a loud explosion sound that lithely shook the truck , steam came out from engine compartment. I shut it down. Found a AC hose that blew off that leads down to the compressor. The hose had a crimped fitting that is gone. Question: what could cause pressure to build up that much to blow crimped hose off, or am I thinking to much into it. Not sure if I need to just change out hoses, or if I may have compressor issues. Thoughts?

Funny stuff. :-) Thank you for another informative video.

i like your methodical approach

i love your diagnosis steps. They help me in Real life situations i appreciate you.

Hello sir. My L300 fb van is a dual aircon front and back. Is it possible to condemn back aircon without changing smaller compressor or condenser. Is there a problem if i only use front aircon and compressor at ease design for dual aircon? Thank you

Back in April I had the aircon recharged on my 2008 Citoren C4 Grand Picasso. It only worked for a couple of days. Dye was added when it was recharged so I found out that there was a leak in the condenser. There were no other leaks so I replaced the condenser. I damaged the end of the high pressure line taking it off so I had the replace that section of pipe. It was recharged again and it is now working. I reckon to have spent just over £200 in total.