Chevy 2500HD With A Bizarre Running Issue

[@G31mR]

"If I'm wrong, we'll delete the video and pretend it never happened." Made me chuckle out loud. You are not only a top-notch wrench, Mr. O., you are a great story-teller. Your kids are fortunate.

[@mikeissweet]

I design low voltage circuits and sensors for a living, and I'm always impressed by your grasp of electronics. You nailed this diagnosis and did a great job explaining it

[@SouthMainAuto]

Fake it till ya make it is what I do

[@jasontexter1721]

So you gonna redesign the "weather tight" connectors 🤣🤣

[@lannyellison5950]

Sight unseen I would bet and take a chance to his getting it designed! He speaks like an electrical engineering Career person!

[@280813jb]

I was an old computer technician from the late 1960s, so no more pull up/ pull down resistors to eliminate floating electrical signals?

[@mod_incllc3235]

@@SouthMainAuto No, this one was a masterclass. Thanks for taking the time to explain. I for one learned something new today. Excellent.

[@YOUZTUBE2000]

Thank you Mr Eric O for inviting me into your shop! I never mind the sound of the furnace, compressor, telephone, and Josh working- oh and your neighbor cutting his grass (he must be scalping it). In my opinion that’s what makes this shop/ channel so great!

[@waynebake1123]

Don't forget the "Hey it's that guy" guy.

[@richard3141592638]

Don't forget the lunch time siren

[@ToddKing]

I don't either. It's part of shop life. I lived it for most of my life.

[@chrisbentleywalkingandrambling]

And the Train, and Shrek.

[@brucelittlefield9280]

I’m a retired Boeing electronic engineer. You have explained it extremely well, you’re really great at this! I’ve learned a lot from you. Thanks buddy!

[@ua7pyro591]

Lol

[@shakey2634]

Hmmmm….. I see some other KZbinrs that poke holes all the time. Great stuff as always!

[@andrewhigdon8346]

@@flightforensics4523happy holidays fellow Charlestonian!

[@davidmueller2780]

The excitement in Eric’s voice when he discovers the thats your problem lady is worth the video itself!

[@99andrianmonk]

Great diagnostics. Most mechanics would have shot the parts cannon and replaced O2 sensors; of course to no avail. The truck owner should be super appreciative that your superior diagnostic skills have enabled him to continue to enjoy his truck. Happy Holidays to you and your family.

[@mariosaccoccio1688]

Eric didn't need to fire the cannon, apparently, someone else did!

[@dennyoconnor8680]

Hopefully that rolling wreck wont kill some innocent other driver when it falls apart.

[@RaiderWolf-yd6nm]

@@dennyoconnor8680 _Hopefully that rolling wreck wont kill some innocent other driver when it falls apart._ As are many I bet in New York and the rust belt. That truck is far from an exception most likely. He isn't an insurance adjuster so as to total a vehicle, which such a vehicle is frequently worked on by South Main. In short, that's no where near a unique case. If you are concerned and live in the rust belt, move.

[@McBuggs.]

@@dennyoconnor8680 Hopefully after the owner finds out from this video, they won't be driving that rotting pile for much longer. I know it'd be a wake-up call fer me!

[@SuperNoticer]

It's not that bad

[@jasonaltham7013]

Had a 6.0 2500 GMC truck where the engine would run fine in open loop but when it went to closed loop would lean out all bank 2 cylinders. What was happening was the ac drain was dripping water onto the B2 S1 sensor connector, shorting the 12v heater ckt to the sensor signal circuit, creating a false rich exhaust condition. The ECM would try to lean it out by reducing injector pulse width to the point all 4 cylinders would misfire.

[@SouthMainAuto]

There ya go. That's a good one!

[@harrywalker968]

thats factory,,isnt it.. why i dont buy modern ve hicles.. too much sht..

[@larryberry2436]

Good diagnostic skills on your part. I hope that you got paid for your knowledge.

[@jasonaltham7013]

1 hour to replace the o2 sensor and grease the connector/ check terminal corrosion plus diag. About 40 bucks.@@larryberry2436

[@JoseSilveira-newhandleforYT]

Great diagnostic strategy, Eric! That problem could send many heads on a wild goose chase.

[@BigDaddy_MRI]

I’ve worked on MRI systems for 39 years. Analog to Digital circuits are genuinely complex. The A/D converter doesn’t care that much about current. (Caveat: it does, but only to develop a voltage). Nano-amps of current when run through an RF filter and fed to an A/D converter will happily work just fine, and provide a digital representation of the voltage it senses. The same goes for a modern day DC digital voltmeter. So just the salt deposit on both insulators acted as a very high input impedance short, and some tiny value of current flow was established. Maybe in the nano-amp range. The ECM A/D converter happily did the conversion and sent it to the digital computer side of the ECM and BOOM, the O2 sensor had an offset. In other words, you nailed it, Mr. O! Perfect description and understanding of parasitic current flow on the outside of an insulator. Nicely done, and outstanding troubleshooting. And if you prick a wire, always seal it up with liquid electrical tape! Thanks, Mr. O!!

[@davidhutchinson6910]

What you just said is true, however, Mr. O thoroughly comprehends all of this interaction between electrical; digital and "the real physical world" . (water; salt; dirt & etc.). These things are not taken into consideration by the "engineers" when they design their equipment. And the interesting fact that Mr. O isn't aware of just how "gifted he truly is" !!!🤔

[@LasVegasVocalist]

I always love your explanations of things. It's always detailed and very thorough. While I'm not a day to day mechanic, your wisdom helps me better understand how things work under the hood, and I love it. Thank you for your service to the community.

[@jakalaraa]

Another brilliant diagnosis from the South Main Sherlock Ohms

[@andrewl9472]

I’m impressed, both by the bravery it took to stand under that truck, and also by chasing a weird voltage reading on the scan tool down to a pinhole in wire insulation and salt. I had no idea that those circuits were that touchy.

[@jerrys2346]

"You gotta know a guy to get a sticker for one of these babies!" There's a quote in every video.

[@jimrodgers3684]

"Oh, look. There's a new sticker."

[@fredfranklin8816]

Great line!!

[@jonnyrockets4756]

No way anybody would have found that. Your a frigging genius.

[@allanpepper9651]

Great analysis as usual. That would have been the greatest challenge for any mechanic/technician/ problem solver and you zeroed right on it. That’s why your the best on KZbin. I doubt any of the others would have picked that up, especially the ones in warmer states.

[@briangreen430]

I live in North Carolina and I am glad to have Eric's videos because many Yankees are relocating here with their rusted out Subaru's.

[@hansjansen7047]

It wouldn't happen in warmer states, they don't salt their roads.

[@nytrortx5224]

@@briangreen430no self respectin’ northerner drives a Subaru 😅

[@23billd]

EE here. Pretty good explanation of a high impedance source, i.e. current source circuit. I'm amazed that you figured that out. You are one sharp dude.

[@Zenergy0101]

Happy Tuesday to you and yours! A 2001 Chevy pickup is a rarity these days in your part of the country, isn't it? You're probably the best diagnostic guy I've ever seen. Keep fighting the good fight Eric O.!

[@Ogdin3]

Looks like the only thing keeping it on the road is the shady safety inspection .

[@tylermacconnell217]

It didn’t look all that bad. Frame seemed fully intact and rocker panels were in place. Just the usual crust…

[@kenj.8897]

​@@tylermacconnell217POS lol

[@SuperSecretSquirell]

@@tylermacconnell217 those rockers are covered by Bushwacker covers. I'll bet they're dust/nothing behind them.

[@lvsqcsl]

@@SuperSecretSquirellYou caught that as well.

[@francisgall6172]

You Mr O are the Sherlock Holmes of diagnostics! Simply amazing. Great job!

[@mrfishbulb7187]

Sherlock Ohms

[@francisgall6172]

@@mrfishbulb7187 😆 lol good catch

[@VashthStampeede]

I hope he doesn't replace, "There's your problem lady! " with "Elementary my dear Mrs. O."

[@bigragu6828]

you saw a strange reading on the scan tool and didnt ignore it. you took the time to double check what you thought was supposed to be the correct reading and redirected your route before calling a bad sensor. that never give up approach to your diagnosis process is what makes you a great technician. cant wait for part 2. maybe bonus footage of fixing the manifold leak. I wirs you and your family a Happy and Safe Holiday.

[@ghall05]

You just saved the earth and unbelievable amount of oxygen sensors and ECMs! A single dealership would have shot their parts cannon at this truck so many times it would have caused a national backorder. Seriously good diagnosis Eric!

[@steveloucks3950]

I sure hope your local folks realize how lucky they are to have such an honest and smart tech. You amaze me

[@MrHunt1701]

"for some reason I doubted mysefl" And this is why your argueably one of the greatest mechanics that ever lived ❤❤

[@gwbuilder5779]

Understanding the sensitivity of the miliamp/volt circuitry can really help zero in on diagnostics. Knowing your influencial environment like salt corrosion whether from winter road maintenance or ocean is huge in terms of where to look for potential trouble spots. Here in Hawaii, electrical connections full of corrosion go unnoticed because there isn't a bunch of green puss around the connection, but that light oily salt film is actually everywhere. I would imagine even there in New York or any seaboard location. I live at 4,600ft elevation, but here in the middle of the Pacific ocean, there is nowhere that you don't have salt air. Excellent catch Eric, perhaps you have worked in a salty environment before.😂 It amazes me how such a slight oily film can affect the sensitivity of electronics.🤙

[@russdavis1960]

THAT was one of those 'who'd a thunk it' type of deals. Great job on the diag!!!

[@learninghowtodothis8062]

Super smart diagnosing. This is why you get the big bucks.😊

[@REDMAN298]

Good find. That`s another reason to shy away from cars that have had too many hands stirring the pot. You can`t tell those guys that they`re doing bad by stabbing wires at random. They won`t listen.

[@dustcommander100]

I think you nailed it. The salt itself is conducting, and is more than happy to reach the conductors thru any pinhole or other means available. Super bad environment up there in PRNY. If a good O2 sensor has a comparatively low impedance to the input of the ECM, having it unplugged (or a bad connection to it) would leave only the path thru the contaminants to determine the voltage - whereas when the O2 sensor is in the circuit, it would mainly be the determining factor. But what do I know? I'm a plumbah, for cryin' out loud!

[@gcrauwels941]

Got to love that salt's conductivity. I once had a customer with a 54' Bertram powered by12V92TA Detroits call me one morning that said one of his engines just started up by itself at the marina in the middle of the night. Went and checked it out, and a pinhole had developed in the a/c condenser water manifold (uses raw water for cooling) that was outboard the port engine. A fine stream of salt water had misted the starter solenoid and lit the engine off. Had to rebuild the starter. Definitely strange, but not hard to find why.

[@kenj.8897]

Good story

[@kens.3729]

A Great Master Mechanic is Always Great to Find. Your Viewers are Spoiled. You’re the LockPickingLawyer of Auto Mechanics. Great job, Eric O. 👍🙏

[@jamiepatterson1214]

Eric, your ability to explain a problem and diagnose it, and why it occurred, explains why others brings their vehicles to you to troubleshoot. You demonstrate a working knowledge about how circuits work, thereby knowing the possible cause and what to look for. You'd be an excellent teacher at a tech school or jr. College.

[@AntonioClaudioMichael]

Wow Eric O nice find On the bare spot on the Wire that is Crazy O2 Sensor Connector All over a pin Hole Prick interesting to see it changes when touching the insulation 😮 29:09 @South Main Auto Repair LLC

[@andyca15]

Remember kids if you are doing the hokey pokey always remember protection, or someone is going to get salty, you'll have someone scoping your undercarriage and get a huge bill.

[@rmproute66]

Per an old saying, “You Do the Hokey Pokey and You Turn Yourself Around, That’s What It’s All About!”

[@johnjaco5544]

Amen!

[@d1sternagle]

Unless you want beautiful babies. ‘Protection’ is a population control method used by the controllers.😜

[@petemedina8446]

35:03 😅

[@joedavidzuniga1993]

😂

[@crautoguy8384]

Man I've been working on cars for 26 years that would have kicked my butt so impressive and educational thank you

[@bartscave]

Man, when I watch videos of the corrosion underneath these trucks, I know I’m SOOO spoiled in California…. But even so, I probably still wouldn’t have figured this one out! Awesome diagnostic skills Eric!!

[@ronhall9040]

your stored understanding of auto electrics fascinates me...another great "Gremlin Hunt" video

[@DM-rp7ps]

You Sir are a Wizard! Thank You from a tail end boomer who is also trying to scratch a living in Upstate NY. My FI knowledge has improved tremendously from nothing due to yours and a select few others vids. You are also a great teacher, and I wish you and family all the best.

[@lvsqcsl]

I had this happen to me years ago; we don't have much salt around where I live. I like you said this truck will never pass inspection. OH! there is a brand new inspection sticker. Not bad for someone that has never had any training. You are a good man, Eric. GREAT VIDEO!

[@PatrickJMele]

Your Experience really shos Eric, thats' why I never miss an episode,

[@alyjaabirbachoo5354]

Thank you so much for sharing this experience diagnosis I would never believe that if I didn't see it 😅😅 you make it seems like it was so easy to diagnose and yet so many of us would be scratching our head with this issues 😅

[@jwboilermaker]

Always good to see Mr. O on a Tuesday

[@kenj.8897]

He shot this on a Monday , I held the camera

[@mikechiodetti4482]

The salt in water finds its way up both the outside insulator and inside on the conductor and the insulator. Once it dries, you got power from the heater side through the corrosion and into the sensor circuit. WOW! Try explaining that to the customer! Good one Mr. O.

[@SouthMainAuto]

You don't haha you just tell them the total lol

[@gwbuilder5779]

​@@SouthMainAuto😂

[@matthewhamrick1099]

Wait til the customer gets a bill for more than the value of the vehicle. I have a 2009 Chevy Aveo with a r-title thanks to a deer. Just put about 1k into shocks struts a bearing 2 lower control arms 2 rear bushings 2 interior door handles rear brake shoes and an alignment

[@454lando]

Great video! Thank you for taking the time to record this

[@petebach7221]

Fantastic work. You saved him the cost of two O2 sensors.

[@71Habu]

One of the reasons I watch this channel is because you take the time to diagnose the real problem. While understand most shops, especially the dealer shops are under pressure to push things through, you actually try to diagnose the problem before fixing it.

[@ejwxb2561]

Great Job t.shooting this! I worked in mobile and marine electronics for many years (years ago) and found the most interesting problems were with discreet corrosion problems like this. This particular one would have likely had me stumped for a bit longer than Eric I think. Well done Sir!

[@alrifainidal]

brilliant diagnosis from the South Main

[@spirokattan3655]

Great observation of the bias voltages on both O2 sensor circuits. Thank you for taking the time to explain circuit operation and diagnostic process!

[@philm9750]

Liquid tape and / or marine heat shrink (with glue) needs to be applied to any and all holes poked in vehicle wiring to reduce chance of wire corrosion and circuit malfunction! Thanks for the videos!

[@johnjohannemann1220]

Excellent diagnosis again. Thank you for always proving that not everyone in our industry is just out for money. It’s refreshing to see people actually honing their craft.

[@ryanallen5334]

That was interesting as hell. You are one smart tech I would have never figured that out. Nicely done

[@JeRKII]

Physically I've been out of the business for a decade mentally not so much. I have to say you really are amazing. I have put a word into a small extended warranty company that if you ever call just pay what ever you say needs to be done. ( pretty sure you won't as it on the other side of the U.S. but yea ). Thanks for taking us along only wonder what your start to real end time is on the diagnosis... Merry Christmas to you, your family, friends, and anyone who reads this weither it be today, tomorrow, next week or next year as there will always be another one.

[@fernando13e]

This reminds me of some things my dad always taught me about electricity, I guess whats happening is some galvanic cell formation due to the salt and corrosion which its reaction is accelerated by you when touching both wires at the same time maybe like how a battery works.

[@ScarletKnightmare]

Mr O, you are a gem of a person and you just saved me a whole lot of trouble fixing this exact problem on my Chebby plow truck. I'll learn proper diagnostics by spring, but this got me up n running for snow season. God bless you and merry Christmas to the family!

[@caig9868]

Eric O's videos just get better and better. Always loved watching him work, but the little roundup at the end of this video makes this feel even more like a training exercise or university seminar. What a pro!

[@dougkubash8673]

Great catch! I've been wrenching for 45 years and you never want to take anything for granted Salt definitely conducts current!

[@russmassery1880]

I've always appreciated that you take the time to explain the issue. And your findings.

[@uhplumber5962]

Great diagnostics on your part. I have a 2004 suburban with a similar problem on bank 1 sensor 1. You have given me some insight on what to look for and it didn't cost me anything except a like. Thanks!

[@Stevme0001]

Cool example. You really are a gifted teacher.

[@peterhodgkins6985]

Therein lies a classic demonstration of the differences between knowing what components individually do, and how systems work. The devil truly is in the details... Great find Mr. O! Looking forward to Part II!

[@MikeSmith-hx5xw]

I bet if you were one of the first videos on KZbin the world would be a better place today. Thank you for what you do.

[@vincentlallo6543]

i really liked this video. my brother-in-laws father was an auto electrician before graphing meters and all the heavy duty diagnostic tools. i remember he had the ability to feel the wire and find where it was broken internally. when you moved your finger over that wire and the voltage went wacky it brought back memories. i am 71 years old and i have not seen this skill many times in my life. i learned a hell of a lot from this video . thanks!

[@smjones4238]

The problem was the endemic "NewYorkSemiconductor", salt, dirt and some come and go H2O. PITA!!! In my pre-retirement days, I maintained a lot of low voltage, PLC input control panels. Spill one nice, sugary soda over the panel, it runs into the switches. NOW, find all of the sugary shorts.... Good Job/Great Video, as ever. Those type of problems pretty much disappeared when we went to touch screen panels to replace all of those wires and switches. Michael in Colorado.

[@joshwilson849]

I don’t want anybody to take this comment the wrong way as I think extremely highly of Eric O and have learned an immense amount from him, and I can see why some of you are mind blown by this diagnosis. But this really wasn’t a hard diagnosis. He knew right away from years of experience what was causing the issue with this truck. Focused on the o2’s and also knew from years of experience that when unplugged the scan tool should read the open circuit bias voltage. He seen a value that he knew wasn’t right, eliminated the circuit at both ends and still had voltage, at that point the chase is on. Not that hard of a diagnosis for a guy like Eric or any really good diagnostician. This reminds me of a truck I worked on a few years ago, it was a freight-liner m2 as i am a heavy duty tech. Customer complaint of intermittently the engine would not shut off with the key off. It was the same result. Voltage carryover from a higher voltage circuit into the ignition switch circuit which was a non current carrying circuit, the module just looked for a certain voltage to determine if the key was on or off. I remember touching the red lead of my meter to the top of the plastic fuse box that had a film of road salt covering it and the top of the plastic fuse box measured 12 volts

[@cliffordkiehl3959]

I learned something today. I always thought it had to be copper to copper. Thanks, .

[@fmerkl]

you the Man !! I worked on the bench '72-'91 , love your line if thinking things through ! went farming !

[@irishbob6771]

you are really good at explaining electrical stuff. thanks so much. always enjoy your videos.

[@donakahorse]

Shout out to those original O2 sensors. Putting in the work. Thanks for pointing this out. Excellent diagnostics as usual

[@steveb6103]

You have no idea how mad I get finding holes punched in the wiring harness! I've had to replace the complete harness on a 2 year old Mack rolloff truck because of one person was punching the wires every couple of feet.

[@cannbudo]

Wow! That kinda blew my mind. Didn't think a short like that was a thing. Thanks for the video! To be clear the ECU sends a bias voltage through those wires so it can check for problems in the circuit. The bias voltage from the heater wire was traveling through salt , and debris outside the wire's insulation and into the pin hole. What a mind F*. I hope you do a follow up video on this one.

[@mikeburdi3464]

Very good, quick, easy to follow diagnosis. I know and appreciate that there are some super smart people in the comments section, but some of the questions and comments I have seen in the past make me question if some people should maybe not touch anything on their cars and hopefully, they aren't mechanics getting paid. But as always Eric does a great job!

[@RJJ6129]

Thanks Eric, learn something new every time I watch your channel.

[@quantumleap359]

I'm surprised the sense circuit is such high impedance, the engineers should realize the wiring harness will be exposed to all kinds of dirt, salt, water, you name it. Any degradation of the insulation will throw the circuit off. Good diagnosis Doc!

[@simonblouin2218]

After 20 years, it's still holding!!!! Not meant to last that long. Remember, someone did this by poking pin holes into the insulation thus compromising wiring integrity. IMO, not an engineering problem but rather a "repair technician" problem.

[@stuckinmygarage6220]

​@@simonblouin2218both? It looks pretty exposed to me

[@mlstrawxj]

Very interesting diagnosis. I would never have thought to check that.

[@tylerwilliams3868]

very nice find Eric O! i love the quick and dirty test of checking the O2's wiring. i hate just seeing " oh o2 code you need a sensor!" no show me a test to prove it. i will be using your method from now on! a few years back had an o2 code that fought me for while and following the diag always came back to replace 02 (clearly wasnt) but the diag flow chart never had you check the heater side of the 02!

[@aarontyrrell2931]

I doubt any of the service techs I know would have caught that find. Nice job Eric!

[@michaeld9731]

This was a super-interesting diagnosis! Thanks for taking us along and 'splaining it all so clearly. Merry Christmas to you and your family!

[@goptools]

Amazing! Salt is a very good enhancer of electrical conductivity. Up in the PRNY, you have your fair share of salt on the roads when things get slick. Electricity is like water, it will flow through any available opening. That tiny poke hole would be easy to overlook. It's also a good example of why you would back probe a connector instead of probing directly into a wire. Great job tracking that one down!

[@jpol3808]

It makes perfect sense to me Eric. 10.5 volts through Eric O...... You are pretty dang bright old son! Good job Eric! Your troubleshooting skills never cease to amaze me Sir! Now on to part 2.......👍👏🏁

[@joesantiso6495]

Makes perfect sense - had this happen more than a few times - road salt on older wires - even if the insulation isn’t poked - be surprised how porous insulation can be - very common here in Pittsburgh - end up fabricating a new harness from the top of the engine down

[@erichagler7842]

THAT ONE IS A DEFFINITLY GOING IN THE MEMORY BANK .... thanks mr. O

[@jptrainor]

Dry finger to finger resistance is 1000 to tens of thousands of ohms. I looked that up out of curiosity when I saw the finger touch test result. So if I understood, the circuit is: heater power wire (voltage source) to pin hole to road grime to dry fingers to road grime on the sensor wire to pinhole on the sensor wire to the computer's sensor input. When the O2 sensor is plugged in you wind up with some sort of voltage divider that is splitting the heater voltage and the O2 sensor voltage, and that messed up result is then read by computer. And to exacerbate that, the pin hole branch of the circuit drops in resistance when it's wet. Spraying water on it might have showed a change on the O2 voltage reported on scanner. Very interesting indeed.

[@seabulls69]

Amazing troubleshooting, Mr. O. Gotta admit, this well seasoned electronics technician is impressed with your skill and determination. I've seen high voltage (several thousand volts) find some odd pathways across non-conductors but never anything with voltages this low. With HV, there's always the possibility of carbon tracks created as a result of arcing across contaminated insulators creating a high resistance pathway from point a to point b. How (presumably) vinyl insulation can become conductive like this is new to me. Bravo!

[@porkchop4604]

Eric your troubleshooting skills are amazing on those CHEEEVERLAYS!

[@johnplump3760]

Diagnosing the stray voltage is a great job. Most people would have overlooked it. I had a similiar situation. I did ignore a situation until the fellow I was working with said that this was what he was looking for. When diagnosing a a situation, I learned that you should NEVER ignore something that seems to be unusual!!

[@jimmydm3]

Going the extra mile really paid off! Great job ignoring the O2 sensors and finding the real issue. I probably would have wasted time looking for a section that was melted by contact with exhaust, welders or whatever. Salt is definitely conductive so it makes perfect sense. The salt is a high resistance path so it can't carry more than a minute current, but it's enough to throw the circuit off. Not that we have any salt damage in this part of the country but I will certainly dab a little black insulating liquid on every time I poke a probe in any wire.

[@thomashopkins2609]

That is wild! Never would have thought of that in a million years!

[@kirbyschneider4187]

Thank you for the recap at the end. Great job as always!

[@bkon4675]

Another fine diagnosis! I always learn stuff when I'm fixing things.And i fix everything. Now, I'm picking up information on my downtime as well. Great show!

[@1976Datsun]

I bailed out when the creaky step-stool showed up but had to come back to try to find the solution. Looks like poked wires caused short to power. Well-done. (Edited for spelling...)

[@chrissingletary2287]

Eric, you truly have a sixth sense when it comes to auto mechanics. Most impressive sir!

[@edchenal821]

Your patience is golden. Good Job.

[@dropinbiking92]

This is literally every chevy of this vintage in my area. I love working on them at this point.

[@fightingfalconfan]

This also would have been sending me in circles! I always get lean/rich conditions confused. Good diag on this one! As a tech I don't think it's worth fixing anymore with all the frame rotting away.

[@spelunkerd]

I never get tired of watching you do electronics diagnosis. O2 sensor circuits are a treat because the tiny voltage produced by the sensor cannot produce much current. So to accurately measure that voltage, a big resistor is present inside the PCM to effectively give a voltage divider circuit, with measurement done between the sensor and the big resistor. Likewise to screen for circuit integrity, bias voltage is applied through a really big resistor in the PCM and on to the sensor wire. That big resistor causes the measured voltage to change even if the short to voltage or ground goes through a high resistance pathway, such as through your wet finger to ground or through a salty track from external voltage along an adjacent wire. So the high impedance circuit design inside the PCM makes it more vulnerable to incorrect readings from short circuits. What I find surprising is the way you didn't get a trouble code for circuit integrity, short to voltage even though the measured bias voltage was obviously wrong. Good for you to pick it up even without the usual clues you'd expect to see.

[@peetky8645]

hey spelunkerd. Enjoy your channel. what "usual clues" should we look for in this case?

[@spelunkerd]

@@peetky8645 There are about a dozen codes, between P-0150 and P-0166 that cover circuit integrity for oxygen sensors. I'm guessing there was such high resistance in the short between the heater and the sensor wire that the readings didn't cross the threshold to trigger a more specific code. Bias voltage for the heater circuit was too close to the same values, although it was clearly wrong on live data.

[@peetky8645]

@@spelunkerd thanks, I will look those up. Do you still have the 5.9L dodge magnum?

[@spelunkerd]

@@peetky8645 Yes, running great!

[@RussianSokol]

Thank you for your videos. Been learning from you for over 3 years, cant wait to learn more.

[@abw121]

Eric, your talents far exceed your humble life! It’s a wonderful Life! When I have Tuesday dinner and watch you explain how you find the fault. I am amazed that you do not have a full class room of young wrenches watching and hanging on your every word! You sir are a sponge! And have soaked up such knowledge that you have to share it! I am so thankful to watch you make something so confusing become so easy to comprehend! If Eric O. can do it, I can do it! Happy Holidays to you and you great family! And Have a great new Year!

[@bobberndt9744]

Amazing diagnosis 😮 Who'da thunk saltwater residue could cause a short 'through' a micro pinhole in the insulating coating of the wire ?

[@327-d2n]

Salt is electric ⚡️ that’s why it’s good to eat because humans are electric

[@akdenyer]

Thanks Eric. Another great video on how salt intrusion on wires can carry a small current. Also why you must put liquid tape on any holes. Just shows how this type of electronics design is a real problem when salty conditions are prevalent. The design could be improved using a lower impedance reference measurement sink in the PCM.

[@dannycole9401]

Very informative. Even though I know these things, you are often looking for a quick fix. I have a mechanic ( like I've said, I'm a boat mechanic now) that just got back from school. He said the ohms law was the most pointless thing he learned when I asked. So there will be a shop discussion. Boats are so far behind on technology. They started using variable cam timing, probably at most 5 years ago. That's why I'm the boss now. Experience

[@montestu5502]

Wow, I would not have expected that. Crazy. Great job at troubleshooting!