Relays- Understanding, Diagnosis and Testing Relayed Circuits-Pt1
Вставка
- Опубліковано 27 лип 2024
- This series will make you very comfortable with relays- not just testing relays themselves, but taking advantage of the fact that you can test entire circuits through the relay port in an engine bay which is far easier than testing wiring under a dashboard or dissecting the car.
Part 2 is Here: • Relays- Understanding,... - Авто та транспорт
You might be the only person on UA-cam that actually explains the right way to test a relay. Even after 8 years, in my searches I haven't seen one.
thanks. ScannerDanner does it too. So does GoTech! Tell ‘em I sent ya!!
I just can't understand why this guy hasn't gotten more subs than he has. He's a mine of information, and he always conveys his diagnosis in such a clear manner - really makes you want to listen. You can tell by his voice how enthusiastic he is about his work. Let's just hope that those 81K are the cream of the crop.
Thanks but as I often indicate, the overwhelming vast majority of the automotive community (98% i estimate) only can identify with spinning a wrench and nothing more. They will never identify with anything you actually have to invest time learning. So yes, my subs absolutely represent the top-tier of the automotive community. They are the ones who you won't see parked outside autozone when they try to fix their car so they have the parts-cannon nearby.
Ppl love bullshit simple, if was talking crap you would see a lot of subs but hes good so they stay away and maybe think he is crazy
Pro trick: watch movies at Flixzone. I've been using them for watching loads of movies lately.
@Malcolm Lucas Yup, I have been using flixzone} for years myself :)
@@SchrodingersBox I found and subscribed to your channel. I've got some engine problems with my used U-Haul truck. It's electrical. When my lights were not working it turned out to be the brake switch. It's a 94 GMC Sierra C3500 with 7.4 with a TBI. The vehicle is running rough and my gas mileage is very poor. The spark doesn't seem to advance on acceleration. It could be the ECM or wiring. The plastic put around the wires was hiding some bare wires. It didn't fix anything. Saw the other video on checking sensors using a multimeter and probe so that you don't burn up the sensitive electronics. Thanks for the information and hopefully it isn't the ECM. I hear static electricity is a killer. I did purchase a grounding wrist strap. Scotty uses rubber gloves.
Matt you would not believe how much your relay videos have helped me! I now have total confidence to perform all these tests which I would not have dared to go near before. Thank you so much - once again you have lifted the fog. I would have to rate this relay series among your very best.
Thanks man. Its one of my favorites too!
how i found you is a mystery, this is such a great explanation on how one relay can be "shared" for control multiple devices,e.g headlights and control room,thank you, this saves me several electrical books
This is by far, the best video I've seen that explain how relays actually work. Plus, great instructions...BRAVO!!! This guy would be an amazing instructor.
I agree..learn something from this scenario.
wow! thanks so much! That is the clearest explanation I have ever seen. I knew nothing about relays before this. - I didn't even know what they were for. I also loved the video explaining how a Fuel injector regulator worked, too. Same clarity. You are a very gifted teacher.
Great vid Matt. Thanks so much. Your wiring diagrams are easier to read than a Haynes manual.
Matt, you may not be a professional mechanic. So, I will just let you know from where I stand. “You Sir, are an expert mechanic!” And, an awesome Auto Tech. Instructor. Keep on doing what you are doing and I certainly appreciate it. Thanks for your help and hard work.
Thanks a million for the videos!! I love the process of eliminating variables when troubleshooting. Keep up the awesome work,
look forward to the next video.
Excellent demo. Great communicater. Wish I had a master communicater like you as my teacher during my collage days, when I did my engineering subjects. I learnt these lessons, then, the hard way!! Matt, thanks a lot for your lucid explanation . It's simply amazing. I hope to see more such useful videos from you.
Thank you so much, I am working on a diesel Blizzard and now I am confident how to check the glow plug relay. Your video was long, but it was excellent and I watched it to the end.Cheers.
Man your really smart. You know your stuff. All your videos are great from your Fuel Trims to MAP sensor and everything in between. You teach way better that my ASE booklets. Thanks for all your videos!
Thanks man! Glad you enjoy them!!
Excellent video on basic testing Matt. Great work. Regards,
Thanks my friend, haven't seen you around for a while. Hope your channel is doing well!
Really enjoy the way you explain things :) great videos
Just finding your videos and you are pretty detailed and correct in what you say. But your teaching skills stand out the most.
Turning over the circuit tester cuz it was scary and complex looking
lmaooo I'm dead 😂 so conscientious of your audience.
Edit. Sp
You’re top of the line, just awesome...Matt 👏🏻👏🏻👏🏻. I became a do it yourselfer for so many reasons. I’ve come across so much BS from “professional mechanics” that just common sense makes me doubt in so many ways...it could be very confusing at times.
A good one to diagnose would be a CCRM to a 1996 Ford Windstar...it looks a bit overwhelming...🤪
Found this page today… awesome content btw 🙌
If it clicks you must acquit.... another great breakdown of the nitty-gritty
Really good video, thanks for sharing!
Most comprehensive. Thank You
The way you wired that relay, when the relay coil is activated, that relay will create a short circuit.
Dude, you are funny as hell.
how stupid. how is that possibly going to happen on the load side? why are you such a dope.
you are very intellectual professor. I enjoy watching your videos at all times and thanks for sharing your know how or knowledge to people like me..
+Santiago Escalambre Thanks my friend!!
Matt. You are absolutely Awesome. I love watching your channel.
Thanks!!!!
A very well organized and presented video.
Thanks.
Glad you enjoyed it!
Really, your vedios is completely informative. Thanks you.
KNOWLEDGEABLE Schrodingers box
Tutorial great video brilliant thank you for sharing what you know with us. Take care and have a great day Schrodingers Box From Nick Ayivor from London England UK 🇬🇧
That was a great explanation of understanding and testing relays. Just found your channel and new subscriber.
Thank you!!
Thank u sir ..its is very educated.i really had a very hard time to understand relay but u just made my life very easy. thanks
Very Very Very informative. Thanks
YOU are a legend, i’ve learnt so much. Everything on my motorcycle works, other than the high beam after I had a low side crash, this has given me enough knowledge to narrow it down.
Its strange as there is not 12v going to the light socket (tried the bulb and it works) but there is 12v leaving the high beam switch on the left hand switch gear on the handle bar when its pressed.
Frustrating but I’m sure I will get there
21ADB21 Simple open in the wiring between the switch and bulb.
Also, your video about fuel trims was very well done! When i was in automotive school I never really got it, but after your video it all makes sense!
great explanation matt thank you .
Thank You well done!
Thanks for making this!!!
Glad i found u on youtube! Thank u
small point regarding to the relay my be the internal switch in NC normally close which means that without applying the voltage for the coil you also will have continuity
not all the relay is NO (normally open)
Yes, it is an important first step to determine whether it is NO or NC.
Thanks brother for the amazing Teaching !.
SWAPTRONICS ... LOVE IT... AME FROM THE DEPARTMENT OF REDUNDANCY DEPARTMENT HEH HEH THANKS FOR SAYING WHAT YOU DO ABOUT ELECTRICITY - MY KID IS AFRAID AS YOU ARE AND ALL SO SAYING THAT HELPS HIM AND OTHERS REALIZE ... ONCE YOU KNOW IT, IT'S EASY
First thing I noticed was the original description assumed the relay is normally open. That might confuse beginners at first but this channel isn't for beginners right? :P I'm early on in part 1. Hope you cover the difference between a 4-pin and 5-pin relay, normally closed and normally open. There are a ton of different configurations. That's why they print diagrams on them so you'll know exactly which configuration you're dealing with. So far this is a great lesson for how to test a relay without any diagram (paper or screen printed on the relay). When it comes to relays that's the most important skill to have and you seem to have a good grasp of it.
***** ya for a 30 minute video he should of mentioned that there are closed switches, usually with a 87a
Awesome tutorial. How anyone can thumbs down it is inconceivable! Going to watch part two now. Just liked and subbed.
Its because 98% of people only understand spinning a bolt. It's pathetic. But thanks for recognizing the value, it encourages me for sure!
Definitely, Keep up the good work. Hopefully, I can diagnose A crank but no start condition I currently have with my 05 Ford Freestyle. Thanks again.
I have tons of crank no start videos and in fact just about to release another this weekend.
The pins are either numbered or lettered on the case.
In the schematic you showed, there was a diode across the coil. There are a lot of relays that have this diode built into the case. Like a tire full of air, a relay coil full of magnetism has stored energy. Then the magnet field collapses it makes voltage in opposite polarity because the magnetic field is moving in the opposite direction from when it was created by the source voltage. So much voltage that it can damage transistors that might be in its circuit. So we place a diode across the coil in such a way that it shunts the voltage during this brief time when the magnetic field is collapsing.
The relay will work without the diode, but if you put voltage across the coil in the opposite polarity from the way is is designed, the diode will short and burn out because of too much current.
A lot of time the ground side if the relay goes to the computer and connects to a collector of a transistor. When the transistor is turned on by the computer, then the transistor acts like a switch to ground energizing the relay. This is why there is a diode installed to protect the transistor.
you remind me of one of my teachers in automotive school! you're awesome! Keep it up!
No, he is way better, way better.
He talks a good game but let's see him do the electrical diagnosis show us how to bypass the relay at the box using the volmeter
If it doesn't click you would know that there's no power to the control side
Loves to talk
You could have blown out your pcm doing that
Very informative! Thank you!
Great work.
What a great teacher....
Thank you!!
Right Matt.... the same electrical engineers that designed the Delayed Accessory Relay to be placed right into the inside of the smart junction box on my 2005 Ford 3.0L. Impossible to repair if it burns or sticks opened or closed. Everything else can be replaced. Fuses, 30 Amp breaker, etc. The things that run the NECESSARY components on my vehicle. The one thing that's only for CONVENIENCE is built right into the Smart Junction Box. If this Relay goes on my car I'd need a new Smart Junction Box. Because I NEED to be able to run my windows, radio, moonroof, and have my interior lights on for 5 minutes after I turn off the engine. Unbelievable.
nice work
Hi Matt, could activate the subtitles in your video please.
another great video, thanks for your work and dedication =)
thank you!
This cat is an allstar, right on bro'!
The best teacher
At 10:20 I was very intimidated. I nearly turned off the video. Thank you for turning it over.
Love it .. keep it up 👍
Thanks ✌️
Thx Matt! FN brilliant!
Thanks
Thanks very much, the video is very much appreciated. I have found the hard way how important to understand the car electricity actually is, which brings me to my question: How do I begin to study the car electric system without having to go to school? I think I'm a bit to old for that! I do appreciate all the help you may be able to give me to understand the why, how, and the what happens in order to diagnose any problem. Or at least get close to the problems at hand. Thanks very much.
visit www.schrodingersboxqm.com for videos that teach basic electricity.
Matt, Congratulations, You took the plunge! ( Electrical Diagnostics ). Suggestion, you should use a test light when applying voltage to the relay not a jumper wire as you suggested. The test light will limit the flow of current should you be on the load side of the relay. Most incandescent test lights will limit current flow to around 200 ma or less and most coils in the relay only need around 100 ma to energize them. I know this was a simple circuit ( I suspect you picked the horn to limit damage should you mess up! ( LOL ) but most circuits ( window, heater control circuits, etc. ) do run thru the PCM or some other computer module on most newer vehicles these days. Using a jumper wire is just way to risky! When using a jumper there is no restricting of current flow and you could instantly fry your PCM!
Billy R Electronic test light I think is even safer personally. Designed to specifically protect the PCM.
One evening my headlights never turn off even if the headlights stalk switch is turned off. I had no option but to disconnect the battery wait until next day and connected back and took it to the repair shop. Now I understand the reason, good to know . Had I known this before, would have tried replacing the relay on my own and saved few bucks.
you do know that you were lucky at 24:00? Your test guessed the horn to be on the ground side but you had no guarantee that it was on the ground side. All of your tests done prior to that had not determined the location. If you were wrong, you would have created a nice short to the ground when you went to blow the horn. Fortunately, your PowerProbe3 has the circuit breaker in it, so you would have been spared from any real damage but personally I think that was not the right thing to do if you are in a teaching mode!
This is true- I was not concerned about the short to ground risk because I knew I was circuit greaker protected. Looking back at it a test light would have been a better way if I had to guess.
Maybe test the voltage drop from the relay load side ground to vehicle ground when the horn is energized. If there is a sizable voltage drop you know at least something is loaded downstream, probably the horn. If there is little drop you don't want to apply voltage.
Very good videos
Amazing video. I have always had a hard time understanding relays. Watching this video made me feel stupid hahaha I've always been able to test fuses. All the wiring but once I got the relay it had me confused but you made it look so easy that even Scotty kilmer could do it... Actually he would probably put in a new one and try to tell you that it's a general maintenance item. And with 2 grunts it's out and in. Presto. You are almost done... Still doesn't work but we can rule out the relay now. Right? Hahaha
Although he says that electricity is not his strongest suit, he seems to cover every aspect of electrical auto diagnosis in his videos. Imagine his depth of knowledge of his stronger suits.
Matt, thx alot! But I've been more of a motorcycle backyard mech. so cars can b a challenge (I just bot an AMG Mercedes!) So what I've heard so far on your horn circuit instruction is the power (red) goes through the relay and ends at the horn (which beeps) to ground. If that's correct then would headlights r tail lights b on the same type of circuit?? If that's so then wouldn't all that circuitry put a great drain on an alternator esp. at night? Or take a cable put it on the + side of a battery and ground it. What happens? Sparks and great heat.
Like u said in the beginning, 'electricity can b daunting'!
Hi, I enjoy watching your videos which are very relatable. Ihave learned a thing or two from them. I'd like to point out that starting on 23:25, your concept of where the horn is, could be a little confusing. My take would be that the horn IS the point where the ground and the hot meet. Both sides of the load circuit in the relay are the "hot", just a switched hot. The actual "ground" side of the load circuit is between the grounded end and the "negative" side of the horn. Keep up the good work !
Hi Matt..just came across your channel....thanks for sharing....One ? if you would might know.... the air/fuel ratio on a normally asperated car vrs. turbo charging that car....does the ratio change with added forced air.
Its a great question several people have asked. I have yet to see a turbo car but if I can get time with one, I'll be going to town on it. All kinds of questions- fuel trim, MAP readings, etc... But for now I haven't even looked into it so I do not know how air/fuel balance is handled or even monitored in turbo or supercharged applications.
'Elektrictrickery...'
'THE Dark Art' of automotive diagnostictrickery!!
Yep for most people by far, electrical and computer is pure voodoo. It is precisely what separates a parts clown hack from a truly skilled diagnostician. It's the electrical and computer aspects.
Great diagrams. @sshats lol v funny and insightful. Thks
Alpine Pat Lol thanks- not everyone appreciates the humor. I love it though
thank you for this video. I learned a lot from your clear explanation. It also provokes a question. At approx 23:50 in the video you did somthing where you might want to warn your viewers. This is where you send 12 volts into the ground side of the relay (horn) circuit. This is done to prove what side of the circuit the horn is situated (I believe you did this because your were certain the horn was located). However would it be appropriate to warn the viewers of the risk of injecting voltage on the wrong side of the load circuit? It seems to me that it would not be a good idea to guess and inject 12 volts on the wrong side of load circuit. Please let me know if you agree or disagree. Thanks.
Thanks again.
can the relay load side ever be on the negitive wire of the device they are powering up or are they always spliced into the positive side?for example instead on a typical 4 pin with relay removed then seeing usual power/ground on control then power/ground on load side could it be power/ground on control then ground/ground on load as its spliced into the ground side instead?
i don’t see why they couldn’t do that but I have never seen a relay with that position on a circuit- it’s always been a power feed that I have ever seen. but of course- a ground side relay should work fine in theory.
ok thanks for that matt!!
not to be picky but voltage does not move it is applied. also current flows from negative to positive. conventional theory has been replaced by the electron theory. this does not really matter with most electrical diagnosis, but does at the electronic level. fine job on explaining relay theory and operation.
Great video. When you were powering the relay up, how come it didn't matter that you connected the negative alligator clip first & the positive 2nd?
It makes no difference because you don’t get current until you get continuity and that can be done at either polarity.
What do you call INTELLECTUAL AND PRODIGY and SUBSTANTIAL add one more KNOWLEDGEABLE the answer is
Schrodingers Box
My teacher
Thank you very much helpful information video tutorial outstanding video 👍 👌
Take care and have a great day
INTELLECTUAL Schrodingers Box
From Nick Ayivor from London England UK 🇬🇧
The power side switch is in the relay. The control switch is outside the relay. The horn is a load.
both power and control sides are internal in a relay
Great channel, love the theory. I had a crank no start engine on my 2001 focus so I viewed this video for some inspirationation thinking. BEHOLD I had a bad fuel pump relay!
Thanks for another great video Matt! Just a little feedback: I think you assumed all relays are Normally Open. If that had been a Normally Closed relay then you would have continuity on both sides and probably set you off direction... Another good thing to do when checking relays is to measure the resistance of the coil. Most cars I've seen, have more than one relay of the same type and maybe a "relative"value between them can help you know if the relay in question is good in the case that you don't have the specs for it.
Emmanuel Muñoz Yes I discuss relay configurations in Part 2 but I did forget to mention resistance in the relay coil- good point.
Yeah, I just saw part 2. Next time I'll wait for the series to be uploaded before commenting. Thanks again!
Emmanuel Muñoz Not a problem, it was valid feedback. I always try to cover everything and leave "no stone unturned" but invariably I miss some things that are important and comments like yours help to "complete" the episode.
You narrowed it down to either an an open on positive side or a bad switch (control side). What if the input was controlled by the BCM? Is this possible? How would proceed to troubleshoot in that case?
Oh that happens all the time!!! in that case you need pull a “computer pinout diagram” and go to that computer or module and backprobe that pin and look for if the signal is there. if it is you know the open is on the wire. if it isn’t there- you need a new PCM. I have quite a number of videos where I show this.
Awesome video. I love watching these because I'm an aspiring mechanic. But I have a question. How could I test these circuits and know I won't fry my pcm?
By knowing the circuits design and function.
And also maybe one of the reasons to use the relay is the PCM which it can't give a high current to all systems in the car it only provides the signal to let the high current activate the component
Hello... I have a question. Why am I getting 3.6 volts on the control negative, does that mean a bad ground. It's on the fuel pump circuit...thx
If you are on the correct wiring and measuring correctly then then yes, that would be the explanation. I would confirm it with a voltage drop test.
Superbbbb
Great video, I’ve watched your channel for a couple of years now and i also subscribed to the SBQM channel. Just out of curiosity, when applying 12V on the Load ground side, If you were not certain that the horn was on the ground side and it happened to be on the power side, were you not concerned with applying voltage directly to a ground, or you knew for sure it was in the ground side.
First, Thanks for the subs! it is much appreciated.
To answer your question, I would know immediately if the horn was power side switched because I would not have seen 12V at the power side. The fact I saw 12V at the power side means that it can only be controlled on ground side- otherwise horn would be on all the time.
@@SchrodingersBox but with the circuit being open, wouldn’t there be 12V regardless of which side the horn was in. From what i can understand is that there is no switch on the load side apart from the relay itself.
not if it was power side switched. Because if it was power side switched you wouldn’t see 12V at the relay until the horn was pressed.... because it’s power side switched. The fact I saw 12V there tells me it must be ground side switched. there is no other explanation.
Try drawing a simple wire diagram out both ways - one with pull up and another with pull down design and you will see it.
have a question matt, trying to get a good grasp on electrical here.... These two vids you clearly show measuring voltage and resistance in circuits which as I understand is safe regarding 12 volts....when would it be beneficial to measure current in a circuit...and for what purpose? ?..as I have read a little that current is dangerous to measure and most dvom's only read max 10A... Thanks in advance! !
Reading amperage is useful because voltage does not mean there is electrical flow. An open circuit is great example- You could measure voltage at a socket with an open- there is potential, but no current. Measuring current may indicate there is just resistance in the socket.
You never wasnt to read amperage without a load in the circuit- that should be obvious because it would short.
At ~23:17, where you talk about giving 12 volts to ground to test the horn, you say the load (the horn) is most likely on the ground side. But what if you lacked that sort of prior knowledge and guessed wrong (i.e. what if the load were on the power side), would you be putting 12 volts straight to ground, creating a short-circuit?
What a great question! no you wouldn’t. in either case- whether ground side switched or power side switched if you make the connection across the relay load side, that circuit will still be open unless that switch is closed.
so in the event of this horn, the horn is always grounded so putting power to it activated it if the horn was ground side switched then you would have still press horn button to activate it.
@@SchrodingersBox Thanks for clarifying. You're content is great, by the way. Thanks for making these vids!
Matt, to fully diagnose relay issues wouldn't you have to test both the control and the load side under actual normal operating load and not just run a voltage and/or continuity test? A length of relay (or other) circuitry that reads proper continuity could still show improper functioning (a large voltage drop) under load, no?
No you wouldn't because the bench test shows the relay is working. If the system is failing under normal load application BUT the relay works on bench test, you either have a compenent failure OR voltage drop/insufficiency issue.
Mat you are correct my dads van fan stopped working I checked relay just by the click but I decided to replace it and fan started working again i was confused i thought the click meant its working
I'm a "UA-cam Certified Mechanic" from watching you're videos. I might even be better than some "real" mechanics. :-) LOL
Probably better than me lol!! At least that’s what a lot of commenters tell me!
Happy thanksgiving brother!
Noob here, are you using resistance option on the multimeter? I thought it could be done in a live circuit. Thank you
I am using both continuity and resistance measurements.
Your channel has changed the life I live in my garage. Really.
I just wish you lived closer so we could drink beers and talk shop.
Plus, I can't figure out why my Golf runs rich. Watched all your fuel trim videos and diagnosing and I must be missing something. @_@
Is it rich at all RPM ranges or only at idle?
Definitely a cold start issue, but continues to run rich even after warm up and driving conditions.
Here's a long winded video that explains some of it.
ua-cam.com/video/WtS2U1WRmpI/v-deo.html
Also, after the video, I went back to the car an hour later and it started fine, SAI pump kicked on perfect, no misfires or overfueling. Turned it off immediately, and it then started it up again only to have what happens in the video happen....
tenor.com/ZWJs.gif
Did you get a chance to look at the video? What are your thoughts?
left comment on your video. Dude! Edit it next time lol!!!
@@SchrodingersBox Have you had a chance to view the new video I made in answer to your requests for data?
i have an 2002 audi s4 wont start after smoking in the coolant container what relay can i change
You can change any relay you want.
Can you do something on inverters & how to choose them on the white board of knowlege? I blew up many fuses trying to power my laptop in my car cause I dont understand why or I dont understand peak powerer, start up power, should I be looking at amps or watts? does higher volts mean more power?
Theres info but nobody breaks it down like you... how long can I run my car battery on a laptop.. should I recharge my car battery... I have no idea with these questions but would love to be armed with the knowledge
Yeah that would be a good topic. I actually once destroyed a scan tool running it on an inverter. I didn't realize it's not the same thing as a 120V outlet.
Exactly... I would have blown it up as well because I don't understand that 120v or 220v stuff.. I just plug it in and hope I don't blow the cigarette lighter, fuse or laptop... I usually do so I stopped using them..
I should have just sprung for the most expensive inverter and hope that works..
At 17:30 when you press the horn button you are on DCV not continuity. You do get a good 12v signal but that's not exactly a continuity test that's a voltage test. If you would have had the meter setup on continuity the meter should have beeped when you pressed the horn. That's a much easier test when you are in the cabin far away from the meter as the audible alert would let you know you are getting the desired result.
***** LOL. Just recommended a 98%er watch this video and spotted your comment. I'd love my DVOM to beep. That would be much easier - it doesn't do that. It's cheap/free with another purchase.
DE Nichols Pick up a Mastech MS8261 for $25 from Amazon. I would easily pay $50-$75 for this meter. It's the same one that myself and many other youtubers have now. Worth every penny. amzn.com/B000FLZDPG
Yeah I caught that too
hey Shrodinger. I watched your fuel trim video. Loved it. I commented today. Question or challenge for you= you quizzed us by saying "if MAF sensor was dirty what would long term fuel trim look like?" I thought lots of un-metered air would find its way down to the O2 sensor. So that would respond by adding more fuel I thought. Hence causing a "rich" fuel trim. But you disagreed by saying it would cause a "lean" reading. Wouldn't a dirty MAF sensor trick the O2 sensor into thinking their wasn't enough air? Causing the ECU to add more fuel? Concluding in a rich reading? Or a higher fuel trim? Keep in mind your my Mr. Miagi so Im speaking about fuel trim because of your teaching. Not trying to challenge or be smarter. Just really trying to clarify.
Good question. You are correct but we missed a bit on definitions. Lots of unmetered air would indeed hit the O2 and therefore the O2 would call more fuel to balance it. This would be a LEAN CONDITION and would be reported by the O2 as Lean. You would see the fuel trim as lean (positive).
However you are correct that the trim adjustment would richen the mixture. This is a richening adjustment however the fuel trim itself would indicate lean. Make sense?
Hey thank you for reply. Yea that does make sense. I’m skipping a step essentially. The unmetered would first cause a lean signal then when adjusted rich. Thank u so much for clarification.
You got it!!
If the switch in relay clicks and has continuity is possible it still can't carry a load?
Yes and in fact I have 3 videos that show exactly this happening.
@@SchrodingersBox Thank you
I have a 2005 gmc envoy. I have a starting issue.if the car sets. Like all night. It starts every day. I can start in the morning and drive fine. When I stop. And park , and go do what Iam doing. I come back and no start. Crank only. Then I have to let it sit again for about 3 hrs. My pwr/ trn relay get hot. Also I can’t turn the key completely to off position. I know it could be many possibilities.
yep many indeed. what data do you have to narrow down the variables?
@@SchrodingersBox I have no idea, I was just reading an article on politico. And sharing fir what is worth.
A 12 volt test light and the proper knowledge of how the circuit works. can tell ya alot
Hi Matt, if you can get an acces to (alldata repair) you will have the data and diagrams of the best in the industry, sorry for my so so english
Yes I now use Mitchell DIY
If you want to make life easier for yourself and don't have any real scan tools, you should invest in a PowerProbe 3 and The Hook. I specialize in computer systems and electrical diagnosis. I noticed you guessing a few times or not checking (Maybe for the sake of the video), but I have used scan tool/scopes that cost more than my car and my $400 powerprobe setup never fails me.
Swot Roke Sorry, Meant The hook only.
Thank you! Excellent explanation of relay basics. Please continue the good work because you are helping people that you will never meet and that makes the world a better place. No reply necessary.
Well a comment like that definitely deserves a reply!!