DIY- Troubleshooting No Air Conditioning
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- Опубліковано 7 лют 2025
- Your favorite DIYer returns from prolonged absence to troubleshoot an air conditioning problem that would have caused Scotty's typical minions to dump $20 right into the ozone layer before they even got a clue.
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.
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.
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.
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.
Learning along from your approach procedure thank you very much
Thank you for:
a) being analytical, and
b) the Devo reference.
More power to you Sir 🙏
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
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
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.
Welcome aboard!
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.
Folks like you are what make this country great. I love calling it home since early 80s. I thank You 👨🏻🔧
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.
Good to know. I won’t change a thing!!
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
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...
What is the low and high side pressure showing?
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
I really like how he explains how to think through what the possible problems are. It's really helpful!
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 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.
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!
I can't see and I thought I was doing this
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.
Yeah my AC video on my pay channels covers these exact variables. A likely variable for this high pressure jump per your description is a clogged expansion valve
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.
Well half the people say to do it more, half say do it less... Since it's my channel I choose to go with the half that says do it more.
Simple to you and very hard for me. Thank you for explaining it for myself. Wonderful explanation!!!
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!
Good to see you again Matt, and hear you bashing Haynes manual jockeys, parts changers and visual inspectors once more!
Glad to see you posting again. I miss your videos the most out of all the UA-camrs.
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 ❤️
I will watch every video you make sir! cant thank you enough.
Exactly.
You make great videos they're very informative ,thanks keep it up
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.
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👀😎
Dr. Schrodinger, you're the best. Compressor running. My low freon was 100 psi, high was 75 psi, 75 degrees outdoors. My mechanic evacuated and weighed the freon, concluded .5 lb volume remained, everything leaked out. Says pressure gauges are useless to tell volume. How can I tell if freon mostly leaked out at home? Runs fine after filling.
Well your mechanic is an idiot basically. Gauges are useless at telling volume in a STATIC condition but the whole point of the high pressure gauge is to assess the reading vs the suction to determine if volume is a problem.
Fantastic job thanks, where are the links to the other videos ?
Lmao damn. I always come back to this video throughout the years. Good stuff
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.
Especially cars from the 90's (like mine) that are now 20+ years old. Resistors and relays have been baked for decades and fail....wiring gets brittle and fails.
I have also used the Devo Diagnostic Technique (DDT) as a problem solving guide for automotive issues. Nice success on the repair Matt
The DDT helped me to. Cranking, no start, so I proceeded to "crack that whip". It worked...lol.
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
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!
Your entrance rant was hilarious
I have a 2002 Mazda protégé. I'm now on a fixed income and have to do all work on my car myself. Thank God for UA-cam. My heater works but not the air-conditioner. The speed switch only works on 4 now, but I noticed that only one pully turns on the compressor/motor. I'm not sure what it is. What do I do to fix my air-conditioner. Watching your video, I guess it's the clutch pull only one turns.
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!!
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 an entire diagnosis and understanding AC series at www.schrodingersboxqm.com. It’s like 4 parts.
@@SchrodingersBox *me gusta* meme intensifies. [Left to go watch immediately.] I obsess on projects to the same extent you put into explaining how things work. I find it to be a mandatory component in the tool box. Thank you!!
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
Using logic then brain contrary to your average mechanic love your video. I can’t believe how many thumbs down you got now we know exactly how many monkeys are out there. 👍
I could tell you’re really frustrated and have no patience with how much idiot repairs you see an air-conditioning on UA-cam it shows, me too !. Some of my videos about air-conditioning I talked to same way in frustration at the idiots and monkeys that you do.
Haha... cheers!!!😄😄
The paid channel explanation is all you really need.
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.
Because, as was mentioned twice in the video quite clearly and also shown on my other video, it was an improperly done butt connection from a previous repair.
I have seen this countless times- clean wire breaks like that at terms and connections. If you do this work with any regularity you will see this very often.
If you really were in the repair market you would have seen this as well countless times.
Schrodingers Box Yes- in 10 years I saw a few "repairs" that were done before they came into the Shop. Always fun- to hear the stories about who, what, and why. Bird's nests of bread twisters, paper masking tape, Duct tape, Scotch tape, bailing wire.
I did hear you mention it looked like a Butt connector might have been used, and had simply broken at the improperly deep cut strip- but there was no view of that broken piece, or of you repairing it in the video.
It seemed like you edited that part out.
I did not see the "other video" you speak of.
I really miss your stunning logic and methodical train of thought.
Nice to see you again.
HUBBABUBBA DOOPYDOOP Thanks man- sorry my answer maybe came off as brash but I misinterpreted your comment. There were several people who accused me of cutting the wire for sake of the video- as if I would do that on a customer's car (or need to do that). It pisses me off.
My apologies bro.
Forget about it. I got just as disgustipated as you about the whole mess- that's why I left, and started an entirely different career until I retired. Don't worry about what the kids here say- they're like flies on a turd.
Brilliant. Nothing better than a logical, sensible troubleshooting procedure. Well done.
Why demean others? Still I thank you for this
I got the very same problem with a 1997chevy S10 V6 , I thank for your help , you're awesome 😇😇😇👍👍👍👍
I like this guy he talks the talk but he walks the walk.
Help please. First of all thanks for posting this great video. Here is my story. An almost similar story made you think AC Compressor Load but I'd like to give you more details.
2012 Malibu 2.4l
Engine was replaced and AC came on and off and then disappeared. At 1st, I thought LEAK...
Please let me point out I have basic or less than basic electrical diagnostic skill.
2 days ago, I decided to check for power and ground at the compressor connector after making sure all fuses and relay were good.
I found a broken power wire (green) at the back of the connector.
I connected the 2 wires temporarily, started the car and switch the AC, the clutch engaged and I could feel the air.
HAPPY I FIXED IT, i just need to connect wires well for good.
Yesterday, i woke up with this task in mind but since the wire cut at the connector was so small, I went to Chevrolet and purchased a brand new connector.
THE BEGINNING OF MY NIGHTMARE NOW.
I cut power and ground wire and, despite trying to be careful, I connected the wires to the wrong sides of the connector, not sure, but I had ground and power at the end of the Compressor connector. Plugged it, started the car and fuse blew. Replaced it, tried again fuse blew 2 times more.
I tried to plug a bi directional scan tool but it would not connect to the control module; it is as if, my scan tool is not plugged.
My neighbor put a wire on the ac clutch fuse to bypass it and I ensure to reconnect the power and ground wire like they are supposed to be. Scantool still can't connect.
IM VERY CONFUSED AND THIS IS WHERE I NEED YOUR LEAD.
1- My first thought is AC CONTROL MODULE BURNED DUE
(I do not know where the AC control module is located).
The AC control panel buttons seems to be working.
2- Could the AC Compressor be burned by the wrong wire connections?
3- Since the fuse kept blowing before we bypass it, I also thought another broken wire but I don't know since compressor clutch still wont engage despite bypass.
4- I get 5V at the AC Pressure switch; could the AC pressure switch be the issue?
What do you think?
Thanks for reading my novel
Before the cream sits out too long... you must whip it.
sounds like my problem too.. Its not just one car your fixing there but i dont have to tell you that. thanks for your time.
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
Thanks for this helpful video; excellent logical approach to an a/c fault. But I don't understand why a cleanly cut wire caused a working a/c to suddenly stop working while driving. Wasn't it more likely to have been accidentally cut during an unrelated repair, causing the a/c to not work since then?
Yes good point. The severed wire was the result of a incorrectly made butt-connection on a previous repair. It appears the crimp severed through the connector and it broke “clean”.
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
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.
not just adding refrigerant but one that contains stop leak and oil. adding more oil makes evaporator heat transfer worse
Yep, nice video, great content, and thank you for speaking to me, EXACTLY like I speak to myself when I spent a $grand throwing parts at it before I researched properly 👍👍
I'm here to make this Video cuz I love to here myself rattle on n on .although I appreciate the help
No I am here to eliminate idiocy in this world. I see I need to focus much more on you specifically. If you would THINK for even just a second, if I just wanted to hear myself talk I would not have to make information you found valuable.
Idiocy. It's overwhelming.
Thankyou for this, fuse was bad but looked good. Swapped to a new fuse and click, on it came
Reminds me of.. me when I am in my shop working. I talk to myself in the same manner. Kudo;s
THE CAT LIVES! Thanks for this no nonsense, quick and dirty video! PROBABLY SAVED ME HUNDRED$
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
You will have to choose what is more important then.
@@SchrodingersBox i like your knowledge but your personality and sarcasm is not a good thing. your smart but dont have great communicative skills..i have been and instructor for investigative teams and your deductions are instructive but your attitude conflicts with teaching..thank you for your channel regardless
@@angelsspirit335 Beta you make it sound like you are some kind of authority or something and I should do things like you do. I am an instructor too. Of 150K followers and MILLIONS of viewers. You should be asking me how I do it because you have not nearly such a loyalty base from your students.
@@SchrodingersBox sorry didnt mean to do anything but express maybe that day of that video you were over emphatic. you know your craft its clear. i didnt take any offense so i dont want you too either. great channel no matter!
What the...? This guy is Awesome! Anyone who quotes DEVO "When a problem comes along you must whip it" scores honors in my books. My books are great books too. Loves this guys personality, sense of humor and auto knowledge. He whips it real good!
Its awsome that you was born with the gift of unlimited knowledge on all cars trucks and im assuming tanks aircraftcarriers blimps and such
hahaha. I was most definitely not born with it that is for certain!! I have spent 8 years learning this stuff and it didn’t come easy!!
Wow! Your in a very bad mood. Go get some sleep and take a shower. Geeze
Love, a Hack
Wow are you kidding?? He filed it didn't he? Sooo the chill, no idea what's wrong thing appeals to you
No bad mood, he's just tired of folks who lack the skill and knowledge he has second guessing him. Plus you should ignore that and appreciate his method.
VERY IMPRESSED WITH YOUR LOGIC. FROM UK.
15:30 you did a great job.
First of all, I am no expert on diagnostics like yourself. With that said I just learned how to use my multi meter because of you. Now, I could really use your help. A/C stopped working during a miss fire on #2 - 2012 nissan altima 2.5 s sedan after I got thru putting on all new coils and plugs. Turns out a plug was bad. During the miss fire I broke a cardinal rule of driving while check engine light was flashing up to the auto parts store. Very violent experience to say the least. So what I've done... I have 13 volts coming out of the power supply lead going to the clutch. Clutch is free spinning from compressor, never had a problem with it. No pulley noise and pulley running fine. Clutch not engaging since the miss fire code, thus no A/C. I think it's something easy like electrical and not mechanical. Do you have any ideas for a guy just trying to do a little wrenching to save money with a little talent I possess.
while there are 13 V to the compressor clutch connector, that won’t account for possible voltage drop. easiest thing to do is apply battery voltage directly to clutch. if it doesn’t work, it’s your compressor. if clutch activates you either have a voltage drop on the wiring OR you have a shorted ground side control.
You should be a Radio Personality on Rock 103 FM lol you rip in to people so calm like...
i like your methodical approach
Me too! Works every time ‘n
Arrogance is definitely not a way to go young man. Check your ego. You can do things without putting others down.
As if you have some kind of authority. Checkyourself I wreck you for looking hypocritical
Great info! blunt and to the point is exactly what this world needs now a days
surprised eric o from south main auto hasn't commented yet! or ivan
They turned it off soon as I brought out DVOM instead of test light hahahaha. Actually I was going to do all the tests using a test light just for them- But at the same time, I also wanted to do this diagnosis conclusively the first time lol.
I generally grab my test light when it's the better test for something or I can't find my DVOM. :)
But then...I'd have to have misplaced my PowerProbe as well, as sometimes I hook it up in ingenious ways just to see the voltage my dvom would have shown easier. Ha.
In the run up to 12:29 in the video you had the voltmeter across the load side relay contacts. You would be unlikely to see a potential difference between the two relay load contacts - even if the load was passing current. With an open circuit as you had, the relay load side terminal would be floating. That is why you didn't read a voltage. This of course changed when you rearranged your meter leads to reference to the engine (which is grounded). If your load hadn't been floating the load current would tried to pass through the DVM.
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.
I don't make these for you. I make them for my fans. Sounds like Scotty Kilmer is more he type of channel for you. You're on the wrong channel.
OK. that's just my opinion. His videos are too short. lol
Paul Wang almost everything he said was straight to the point. Without his words, you wouldn't know what he is doing. So listen and shut up.
you want him to be you? That him at his best. What's wrong with people nowadays. No patience at all? It's a video. ffw if you want, or increase the speed of your video in setting
+TimezUp23 get a life asshol.
It's good to see someone discourage the blind use of freon. But I believe if there is a compressor failure you will need the freon after replacement
On compressor failure the proper procedure is to recover the existing freon (if any) and recycle it after new compressor is installed.
Great video, but do you you have to put put down other UA-cam channels and/or people that comment? Youre putting it out there, so you shouldnt expect all positive responses, man. Very arrogant......sorry
Ummmm, how is this any different than what you just did? Why are you not holding yourself to the exact same standard, especially considering you aren't contributing anything while I am?
Please explain. Because you sound both ignorant AND incompetent to be quite honest. Just giving you constructive feedback man.
Im hardly arrogant, just watching your video should tell you that. And as far as incompetant, how can you tell? Ive been doing this a long time but I do watch videos to help me with some of the new vehicles. Saves me time. All respect, but yours wasnt especially helpful, turned it off early, man. Lol!
All i’m saying is I am holding you to the same standards. That’s all. You are welcome to learn from me but you don’t set the standards.
No you fail to understand. I set the standards. thats why i deleted your last comment. Got it yet? Now be a good little intern and keep learning. Otherwise i’ll set them even higher.
Why have you chosen to be so defensive with potential subscribers comments. If they all seem to you like rubbish ignorant kids who are just posting dumb comments on your videos than why not disable the comments altogether? Would seem wise given that after just reading 2 to 3 of your back and forth replies to comments has me understand why it is that your channel stands where it's at. If you could ignore your unnecessary catty need to speak negatively on other specific yt mechanics, your videos are informative and would be helpful to the less inclined in auto mechanic repairs.
Now with that I couldn't support your method or belief in teaching, so I'll be sure to avoid your channels videos in the future which I can guess you won't be bothered by that but also I'm pretty positive that I'm not the first to think this way.
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!
Blair witch project quality
If that means its good- then you're right.
One hell of a diagnosis sir, you might have possibly saved us so much time and money. Thank you
You forgot the first step: Verify the complaint.
I don't need to- I can see the clutch does not spin. It can be inferred the complaint is valid.
perfect video. I want to see what if the receiver dryer is an issue. what are the step need to do.
Once you determine the low side blockage is due to freezing water, the desiccant would be your suspect.
Also- ALWAYS change the accumulator and desiccant anytime the system has been open to atmosphere.
My complete air conditioning series is at www.schrodingersboxqm.com
I never get tired looking at this guy’s videos. I’ve learned a great deal from his videos and I thank him and others,like him,for sharing their knowledge.
Thanks man!
Unfortunately, I was one of the DIY hacks that started with the addition of refrigerant. By the way, "if it were spinning". Finally, someone who knows when to use "were" instead of "was".
Hahahaha- well "guys don;t make passes at girls who wear glasses" but "chicks don't get intimate with guys who are illiterate!"
LOL If only that "were" true.
you're my hero. i want to do what you do, now. i'm legally blind and can't legally drive but i LOVE cars and fixing things in general. since i get disability i don't have to work but i can't sit around all day watching gameshows. i'm tempted to post on craigslist for free car repair. advice?
Well for what it helps i am legally blind- completely blind in one eye but luckily i am correctable to 20/40. My sympathies bro.
20/80 optic nerve hypoplasia. how often do you get to hear "you don't seem like you're blind"? it's precious. my sympathies as well. you're a genius and i am forever grateful for your youtube series :) keep up the awesome work!!!
I am retired now but years ago I had a clutch problem on an International 9670 tractor. I had 12 volts at the clutch (by vom) but it would not engage. I could put 12 volts to the clutch from an external source and the clutch would engage. I switched from the vom to a test light and found that the problem was a faulty relay. The internal points of the relay were burned but still making contact enough to read 12 volts but not enough amps to even operate a test light. Replace the relay and problem fixed.
Great example of why a voltage measurement is not enough-. Also a voltage drop test would have detecting this.
Nicely done! I wish all problems were that easy to diagnose.
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
Thanks for the add, good to watch someone do things with finess.
Good job shroodinger.. I think I have the same problem.. I have a 1999 Ford F250 Super Duty.. I sent voltage to the compressor and it clicked.. Checked the low and high pressure switch, good..
I think I have a break somewhere or a faulty control module.. Because the compressor is working.. I ran 12volts to it while it was running.. Low pressure was at 40..high pressure at 210..
Static pressure was a lil weird though.. It came out to 350 on the low side and 150 in the high.. So I'm thinking thier might be a restriction somewhere also.. The trucks been sitting for 2 years.. But it's in good condition tooken care condition..
Well if have any advice send me a few lines.. Thank you for the wisdom.. 👍
yep sounds like same issue. And a power issue at that since if you add power to the clutch directly it activates so ground has to be good. I would check for power to load and control relay ports and apply power from the load side of the relay. this will tell you exactly where the issue is.
@@SchrodingersBox OK, thank you
This was a great repair as always. I was about to see how exactly you troubleshooted and diagnose the problem. I would like to watch a video on certain vehicle which is using scan tool to repair the air conditioner. I don't know what exactly the scan tool is doing in air conditioner repair process but I saw a few guys using that on some specific make and model air conditioners. If you have idea, please explain and if you may upload a video sometime when you encounter to one that would be a great help. Regards,
I've had experience with w203 gen Mercedes that once the gas is low they log a code in the ac control unit and even when the gas is refilled the compressor won't turn on until the low refrigerant code is cleared.
Most modern AC systems are integrated in to some sort of body control module and as such they can be checked via any decent scan tool.
The scan tool can often detect system pressure and pump rpm as well as lots of other stuff and can activate fans, flaps temperature control etc. It can also give you trouble codes to aid in the search for a problem.
Although handy the scan tool is never my first tool in AC diagnosis.
A basic methodical thinking approach like in this video will often find the problem way before you even get the scan tool out. Is the belt still there, does the pump turn by hand, is there system pressure, does the pump turn when you switch on the AC system?
These 4 basic things will very quickly, as shown here, help you decide whether the issue is mechanical or electrical and can be done in less than 5 minutes.
In this case the fault came in suddenly so this would more likely suggest an electrical failure of some type.
Also a scan tool is not generally used to repair a problem (with exceptions IE reprogramming), more to diagnose it.
From an auto tech with 40+ years in the trade, this guy is probably the most methodical and knowledgeable DIYer I have seen on UA-cam. Certainly way ahead of some so called "professionals"
Calling him a DIYer almost seems derogatory and this is certainly not intended.
Perhaps "Non professional" would be a kinder term. :-)
Did the DYI work on both our car's A/C systems. Found out that oddly VW systems do not cycle the clutch, but are always 'on' during A/C operation. Lousy design. I replaced the clutch with a used one (5 bucks as opposed to almost 200 as you can't buy just the electromagnet) It already failed several months later. Open circuit. Simple ohm check. With mine? Needed to give the system a part charge with U/V tracer. Blew great cold! But the bottom of the receiver dryer had a hairline crack/hole. Always do the simple basic checks before tossing in a can of R134a. (of course, know what to look for! and have an idea for direction as Scanner Danner would say)
I don't understand how you had the probes for testing the pressure switch. It had no volts then you unplugged it and there was volts and you determined its working. Thanks for the video....
Yes. plugging it in stopped the voltage drop because switch was engaged. That’s how i lnew it was working.
It’s not shorted out, it’s the same voltage on each side of the closed switch so since there is no difference in potential the meter reads zero. Therefore, the switch is working.
Mate, you are a very good explainer, thanks a lot for your time.
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!!!!!
Awesome Diagnosis, my AC stopped cooling but the compressor kicks in, I put refrigerant in still hot air, Any Suggestions I would Appreciate. Thank You
What are the high and low side pressures showing?
Nice job Matt glad to see you on here again. Hey you didn't use your load pro, I'm getting all teary eyed,lol.
Some people do not have any mechanics build I do not know how to check how big electrical system on an AC system so when you go to jump start an AC system you have to make sure the you have the correct wire for the positive and the correct wire for the negative when it comes to the pressure switches especially a three wire pressure switch do not put power directly into the wiring harness on the pressure switch when you have the ignition switch on you can use your voltmeter and ammeter to check to see if your having voltage but do not feed voltage into the wiring of the pressure switch for AC compressor wiring but you can jump start the AC compressor disconnect the wires from the AC compressor if you jump start the AC when you're disconnecting any type of electrical connections turn off the key these are simple things that will help you I hope my information has helped people some people don't know that you have to shut off the ignition switch before you take off I'll kiss him back any type of connection I hope my information has helped you everybody have a good day yes you need to know the theory of how the air conditioning system works and there are a lot of good videos on the internet to show you how to do things
my mechanic has replaced all components. still not working properly. he advises the compressor is not coming on because the circuit blew and i need to replace the engine computer.. He did test system and it holds freon. compressor is new. the max light does not come on on the switch. my question is how do i know the switch is not the problem
You just check for continuity at the switch. Or simply bypass it and see if it works.
Great song lyric: "I have no objection, to a visual inspection, I have an objection to a visual inspection, when you have no idea what you are looking for...."!!
Hahahaha- you’re the lyrical Jesse James!
I like your perspective on diagnostics on a automobile!
Good diagnosis...however, I am not sure how the fix was done since I did not see you fix the cut wire. How where was this wire supposed to have been connected to?
i just did a simple soldered butt-connection. The cause of the failure was an improper crimp connection by a previous person.