I know this video is like 8 yrs old, but I am so glad it is still up. Yesterday at the car show, a fan came up just after I pulled in and parked. He was sharp. He noticed right away one of my dual elect. radiator cooling fans was not working. It has a built 460 in the 67 Mustang and it has been running hot.(It is also very hot outside too). I planned on putting a toggle switch in anyway so I can turn them on earlier rather then when it is 185 deg or higher. Wired up the toggle switch, and test both relays for the click. Will finish up with the resistance check tomorrow. Thanks so much for sharing this info. It has helped so much. Cheers from Motown.

A couple basic tips for those who don't know: A normal switch has 2 basic states, normally open (NO) or normally closed (NC). When power is sent to a switch it change states, so a NO switch will become closed. That means power will be distributed to any legs designated after the switch. A NC switch does the opposite, when signal power goes to the switch it will open the circuits, terminating power distribution. Troubleshooting note: A digital multimeter had two fuses. One for checking voltage, and one for checking continuity. ALWAYS check voltage before checking for continuity. When checking for resistance the meter uses its own power to test the circuit. If there is voltage on the circuit it will automatically blow the fuse because you're checking resistance on a hot circuit. Check voltage before resistance and you'll never need to replace fuses or worry about testing a hot circuit

@Gambit-jo4rw

Жыл бұрын

This was a good video because it’s for visual learners. Your context helps people who like to read but not people who can concentrate. Granted theirs good info it doesn’t help at all for some people, perhaps you can also start a KZread channel to share and explain?

@ProfessorDopefiend

Жыл бұрын

​@@Gambit-jo4rw ty

@terminator7137

9 ай бұрын

COULD you explain this more?

@carleynorthcoast1915

9 ай бұрын

I installed an in-line fuse because I often leave the lead on the amperage terminal.

@fredsanford336

3 ай бұрын

@@Gambit-jo4rw Oh are you a special Ed teacher? Stop trying to impress people with your visual learner nonsense

This is one of the most well laid out and simple to understand vids on relays. Thanks for not making it to complicated.

For all the questions about "Make sure the ground is connected to ground and the power goes to power," ... Typically- pin 85 is ground (negative) pin 86 is power (positive) pin 30 is constant supply power to whatever is being activated by the relay pin 87 is the output of pin 30 when it gets switched on. 30-->87 To be certain which pin (85 or 86) is positive or negative...the diagrams often have a symbol of a diode (triangle and a line) on either pin 85 or 86, whichever pin the "line" side of the diode symbol goes to is negative. Connecting power backwards will simply do nothing, this is what the diode does.

@manmani2463

9 жыл бұрын

thank you for information on positive and negative which wasn't in there

@lexsoft3969

6 жыл бұрын

Actually the diode is inserted across the solenoid for safety reason during deactivation phase.

@FayazShaikh

5 жыл бұрын

Thanks mate

@terijune3307

5 жыл бұрын

Thank you. While this young man is great and I've been learning alot, you read my mind on the little pins, and where they went. Being a beginner I'm soaking up all the info I can. I went on your channel to see if you had any instructional videos on Multimeter checking. To me that is the most daunting as it's so specialized. Repairs of the body of the vehicle and all the other things are great but am looking for more videos on this very specialized information...multimeters and how to check fuses, relays, and wires, etc so we can figure out why our power goes south in our car batteries, despite starting out with a strong and new battery. God bless.

@COMMANDER-ONE

5 жыл бұрын

I just bought a new relay and it doesn’t have any numbers or Diagram on it. How do I know which is Positive and negative

Great job keeping it simple. Other videos go to deep in all the functions of a multi meter. I'm new at this @ 63 years old and starting a new hobby. I am intelligent, but, just never tried learning about cars or electronics, as my career was in sales. Thanks fir talking to me simple, with integrity.

Best video on relays I have seen so far, simple, well explained and easy to follow for complete beginners like me. Well done!

Ratchets and wrenches, love your videos. I just wanted to add one thing you forgot to mention. 95 percent of the time a resistance or continuity check is perfectly fine but sometimes a bad switch will show good resistance but as soon as you load it with more current than what the multimeter can put out it will go back to an open circuit. This concept burned me a couple times before I understood it and will make you go crazy if you aren’t aware.

@joecualquiera

2 жыл бұрын

Also not to forget, temperature plays a critical role in this. Some relays will act up jerking when the engine bay is hot. Under heavy traffic or traffic jam (stop and go traffic) or also under low freezing temperatures. So those cases are a little bit harder to diagnose because basically you want to wait until those conditions happen to test them. It once happened to me. Just my 2 cents.😁🙃😜

@markh3478

2 жыл бұрын

@@joecualquiera Amen to that ! . I replaced all the relays on my 1987 BMW M6 with Tyco and Bosch relays for prevention of possible problems. Then I started getting full throttle power surging. The new fuel pump relay appeared to cycle open -closed under load and hot southern climate. Put old one back in - problem solved. Maybe the diode-resistor combo on the new Brand A relay was a little different than the original Brand B relay.

@iwishtobetexan6060

2 жыл бұрын

Could i use something less than 12 volts? Like a 9 volt battery?

@MistyHilton-ds8zf

Жыл бұрын

​@@joecualquiera P000😊

Watched a couple of videos for testing relays and this was the most direct approach and easy to follow.Thanks.

Check The OHMs on the 2nd relay without power being connected between 85 and 86, Then you will get the connection of 30 to 87 that you had on the first relay. Relays can be (NO) normally open 1st relay tested OR (NC) normally closed 2nd relay tested. Had you checked both relays with power applied and without power applied you would have found both relays to be good. Just that one completed a circuit and the other opened a circuit. Relays can also be (Single Pole Single Throw)(Single Pole Double Throw) (Double Pole Single Throw)(Double Pole Double Throw) That is the reason most relays have the diagram on them so you know which one you are working with. Had you looked at the diagram closely on your relays you would clearly see that the first shows to be closed between 30 and 87 and on the 2nd to be open between 30 and 87 meaning when energized 1st relay connects 30 to 87 and the 2nd disconnects 30 to 87 . Note when replacing any relay not only do you need to how it works to say it is bad, you need to make sure the replacement operates the same way. Or you can create a bigger problem than the one you where trying to fix. Thanks for the video it is done very well and is informative and a great way to test relays. Just make sure and test your relay with power and without power as you did on the 1st if it switches from on to off or vise verse chances are the relay is good..

WOW, thank you for putting together such a good lesson. Straight forward, and will really help me confirm if I need a replacement relay for my fan. You are doing good for the little people! Thanks again!

@tlkeefer0120

4 ай бұрын

😅

Very good info for us who are "challenged" when it comes to electricalal tasks. Thank you.

Thanks to you, I found my problem so much quicker. Relay was clicking, but no resistance. Much appreciated.

The flapper is called a contact. Thank you for the videos! Love your channel ❤️

Your explanation was simply the best one! I made me remember my school class about sensors and switches. Thank you so much for your video material.

The “flapper” is a switch. I’m studying to become an electrical engineer, and I’m having car issues which brought me here. You have a really good intuitive understanding of electrical circuits. You should buy a breadboard and dive in a little deeper!!

Outstanding video! I am working on a RAT PASSAT, and I think now I can finally test relays, THANK YOU!

@myRatchets

8 жыл бұрын

+Randolph Leslie Smith np, glad you liked it.

@muhmmedakramabdulsattarmuh1796

6 жыл бұрын

Randolph Le slie Smith

I appreciate this. I'm having to hunt down individual components for an appliance controller board that has multiple relays. Watching circuit board videos, they just touch contacts and don't explain why. This makes it more understandable and by your explanation, theirs are incorrect. I am extremely grateful for this! Now to figure out how to run a current through without desoldering the individual relays. 🤔 Can't clip onto anything... I'll probably need a spare pair of hands. Thanks again. You're a gem.

Thanks bro...you just fixed my Polaris Diesel. I've been hunting the issue for days and days!

Excellent video. You have a natural talent for instructing people about technical things. This really helps me.

to check what is positive and what is neutral or ground switch your ohmeter to volts and check to a known ground source

Good video on continuing to verify that that flapper, normally opened: bridge,switch,etc. has the continued loop for that circuit.👍

SO FAR THIS VIDEO IS THE BEST TO UNDERSTAND CLEARLY VERY SPECIFIC AND SIMPLE, THANKS, NO WAY NO GET CONFUSED, OTHER VIDEOS GOT ME FRUSTRATED I KNOW SOME GUYS MEAN WELL, BUT THIS ONE VIDEO IS RIGHT THERE

Clearly describes the process of correctly testing a relay. As shown, one can't rely on just the sound of the relay "closing", supposedly completing the circuit. Educational video, well done.

@myRatchets

9 жыл бұрын

Glad you liked the video, thanks for your comment. cheers

The flapper is a switch...one of the few things I learned in college. I love the footprint on the floor.

Correct terminology of a relay, solenoid, or contactor. Normally Open N.O Normally Closed N.C. Common (basically the part of the armature that has constant power to it- depending if its a single or double throw set of contacts. Armature- the little copper arm that gets pulled down when powered to change states, then spring returns back to de-energized position. Coil- Literally a coil of wire (A1 & A2). When voltage is sent on the hot side (or negative side if its a DC coil), current flows through and creates a magnetic field just like a motor or transformer, which pulls the armature down to switch states on the contacts and keeps it in position until the signal being sent to the coil is switched off. Hope that clears some things up. There's a ton of other details about control devices like these but this is the basics... Terminology matters in this field of work!

Just what i was looking for. A well explained procedure on how to test a relay the right way. Thanks very much for posting.

I have been watching DIY car repair videos on You Tube for awhile and you have some of the easiest, most useful, and simply best videos out there thanks.

You might have just saved me these days of looking for a problem that is not there. THANKS!

Wow. I just tested a relay on my Nissan Frontier. Got the relay to click but when checking with the multimeter I got nothing. Would not have done that second check without this video. Thank you.

Looks like I came late to the party, but great vid .. well explained. As to the "flapper" you can call it a "switch", which is all that any relay is. As to the second test, most people forget that mutimeters are protected against significant voltages and IF that circuit was being completed, the meter would have read a resistance of zero, or close to it (all wires, even those used to supply electricity to our homes, have a little resistance, though it may be below the capacity of the meter to even measure). Final point, the symbol, Ω, is the Greek letter "Omega" .. sounds like "ohm-A-ga" (not proper phonetics, but illustrates the connection :) ). Love your videos, and have been recently applying them to a car that cranks but won't start .. major pain!

Extremely well done. Clear and concise and removing all assumptions.

really good presentation of how to get power for bench testing. and explaining the diff between good and bad parts i have seen the half hazard testing. kudos

G'Day from DownUnder Sydney Australia I love what u did, every little bit helps thank u matey, have a great day :)

You are by far the best teacher on youtube when it comes to cars!! Very insightful and easy to understand. Thank you so much ratchets and wrenches love your work!!!

Rather than look for a certain resistance I set my multimeter to continuity across terminals 30 and 87when energising 85 and 86. Appreciate the video!

@myRatchets

9 жыл бұрын

cyborgevo1 thanks for your comment. cheers

It's called an armature. The switch inside that opens and closes due to magnetism of the circuit when power is supplied. This video is helpful but may be confusing to many foreign car owners. The testing circuit isn't always 85-86. You need to carefully read the schematic on the side of your relay. 87 will always be open, on some relays 86 is a ground, on some it is hot and carries a voltage and on others even more confusing it is completely unused. Like certain VW's for instance. The easiest way to realize that 87 will always be open, so on a 4 pin relay that leaves 85,86, and 30. Usually on most relays 30 will be hot, son on foreign vehicles that don't use pin 86 the power circuit will be 30 to 85 which will close the 87 circuit and send voltage out. Because all relays especially on foreign cars are different you really need to learn to look closely at the schematic on the relay and not be so trusting of these videos.

@7777Lace

9 ай бұрын

What if it’s a 5 Point Relay, from a 1991 Lincoln Mark Vll & there’s no schematics on the outside of the Relay? The Relay in this video is from a vehicle more current than my 1991.

@themetalprincess

9 ай бұрын

@@7777Lace I would look the information up online, or I suppose you could just try all of the different pin variations to see if you hear the armiture kick over when applying 12v with low amperage. I've never seen a relay without any markings. It must be generic, you could try looking up a brand or stock relay to get a better picture. Most all stock relays will be marked. Best of luck!

Well done , much appreciated , " double check " that's going to echo in my head , thanks to your efforts .

also the schematic on his relay cover shows a diode, so above 85 there is an arrow pointing to a line, the arrow side is positive the line side is negative

This a step in the right direction. You should really use something other than an ohm meter to check the contacts. It's possible for the meter to tell you the contacts are ok but the contacts fail under a real load like a light bulb.

its always nice when they have the exact same multi-meter as the one you're using

@Legenddjt

4 жыл бұрын

Harbor freighr special works fine

@athensboy123

4 жыл бұрын

Haha I have the same one to lol hell the name brand ones are $20 or $30 I was like screw it i need to go cheap lol parts cost enough u know

@bradleyschatz1714

Жыл бұрын

Harbor freight for the win!!!

If one is not skilled using a multimeter then the next best thing is switching a known good relay to see if the failure persist. Your video is really good,well explained

It has been a very long time sence I have tested a relay. This video has been helpful.

Finally, A quick and simple explanation, on how to test a relay. None of that theory shit. Thanks so much RnW!

In like the way you explain things. Obviously, you got stuck on the word "Switch", but watching this and your other videos, its very clear (despite that one small hang up that occasionally happens to us all) you really know auto-mechanics. Thanks and keep 'em coming.

Thank you . I have a CEN-TEC relay tester tool that does both the switching test and the continuity test at once BUT until I saw your video I didn't fully understand it was doing that. Just toggling mode 1 and mode 2 on tool and matching readout to answer in booklet. So I am like a kid with a calculator that didn't learn to add. Thanks for teaching .

That "flipper" is actually magnetically activated, and the contact looks like the points in old cars, but on a 5 prong resistor, the point is double sided. You video is really good, it helped me tremendously.

VERY EXCELLENT IN YOUR FACE - DIAGNOSTICS ....VIDEOS YOU PRODUCE .... VERY CLEAR , VERY VERY EDUCATIONAL .... GREAT JOB MAN!!!!!!

Wow. You just saved me some frustration. Not less than 3 minutes ago, my 98 accord's condenser fan relay clicked - tho' the condenser doesn't work w/o bypass to battery. THEN I saw your resistance test - bam. No change from the 1! Thank you for this.

@myRatchets

9 жыл бұрын

youngdrjung Hey np, glad you found it useful. Cheers

You can do this with a 9v battery. The posts fit perfectly across the terminals.

@chief1223

8 жыл бұрын

thanks for the tip, was going to jump from the car battery lol

@CarsSimplified

6 жыл бұрын

I used to do that at the parts store to test both relays and headlights. Gotta make sure it's a strong one, though. Nine volts is only 75% (or less) of what the relay is built for and a weak battery may not be strong enough to flip the switch. In the store I would test the old and new one just to be sure I wasn't getting a false result due to the lower voltage.

@dannytheman2217

6 жыл бұрын

you can also daisy two 9 volt D batteries to get 18 volts

@dukejr9490

4 жыл бұрын

Volts and ohms have a relationship, so its scaled, so 9 volts has the same proportion of resistance as 12 volts would

@laragreene8328

4 жыл бұрын

hOW DID YOU KNOW i WAS WONDERING WHAT TO USE? lol THANKS!! 👍

Thank you for that video. I contacted three auto parts stores in Atlanta each told me that a Starter Relay cannot be tested. I will try this method Thank you.

Spent DAYS searching for the problem for this very reason.If only I had seen this video YEARS ago

Is 10 MegOhm Impedance necessary for safe testing of automotive circuits and if so how do you tell a particular DVOM has that rating?

That's the same relay for my 2007 BMW 328i Fan 👍thanks you saved me alot of time and taught me something!

Pretty cool. I've just bypassed the relay before to see if it was working. If it works then relay is bad if nothing happens something else but still could have a bad relaybut this is cool also. My grandfather had a truck and the garage told him fuel pump was bad so I replaced it not testing it first thinking the dealership knew what they were saying anyway the new one didn't work so I bypassed the relay and it worked, put a new one in nothing tried relay in another spot that worked just not fuel pump lol. I eventually put the relay back in and run a jumper from the remote wire on the safety shut off relay to the fuel pump relay and it worked for 6 years no problem when he traded it in lol.

Thank you for teaching me this test!! Best relay test video in the world.

This is a great vid, very informative. I'd love to see you script it so runs smoother but it's the shizzle.

This is hands down the best video!

Thanks for the video, it helped me diagnose and fix the power windows on my 89 Benz. Bad relay! Thanks again!

@myRatchets

8 жыл бұрын

+A. Wild Glad you liked it, thanks.

You are very helpful to us learning about relays!!! Keep up the GOOD WORK!!

This guy is great! Thank you for explaining how to test a relay in simple terms and clarifying why the resistance is important .

Good training, Im learning all types of mechanic in U-tube, Thank you, Thank you-tube.

great video man, short simple and to the point

Thanks for this video! My rear defroster in my 2003 Acura TL wasn't working. Power light for it would come on but no power was going to the defrost grid on the window. I removed and checked the relay with a 12V power source and it clicked, but no reading on the other leads. Just ordered a new relay and hopefully the new one solves the problem. Thanks again!

Good video, no useless info

Thanks for putting it in layman's terms so I could finally get it!

The coil magnetizes the iron core which pulls the lever holding the switch closed! anatomy of a relay :)

fabio sarmento: "I've always been teached that we never measure resistance in an energized circuit. Can you explain me how it is possible? thanks" This is generally a good way to burn out your ohm meter. With relays it's kind of a moot point since rarely do they connect the coil lines to the switch pins since you can just do that on the printed circuit board, anyways. If you want to be sure it's safe, set the meter to volts first and make sure there's a 0 reading. Then you (probably) won't damage your meter. I tend to use $3-5 meters for ohms, anyways. Best not to use a $100+ meter for ohms on a circuit with a battery/AC/large charged capacitors on it.

Well done. Your technique ia correct and your information is as well. Don't let these negative comments get to you. Even when you use incorrect terminology you get your point across. That is what is important and that is the bottom line.

ABSOLUTELY BEST EXPLANATION. Thanks so much!!!

Ratchets And Wrenches thank you for this video

Very good explanation you explain it so the average person can understand

For a Basic check,I enjoyed the info.

You are the man! Thank you so very much for this video. I have two after market relays in my Porsche 930 that i have checked about 10 times with the click test.....Both are actually stuffed! Fingers crossed she will start in the morn!

You save me spending a lot of money on relays great video thanxs.

@myRatchets

10 жыл бұрын

Np, glad to hear it. Cheers

@ryanlane2001

10 жыл бұрын

10-4

@stacyolson562

9 жыл бұрын

Hey why haven't you got back to me yet

Never mind. I saw your other video on how to test for 3 pin relay. Thanks for the great vids.

Awesome bro, very clear and to the point. Oh and we usually call the "thing that closes and opens a series an "arm". Not sure thats the right terminology, but thats what we call it. Anyways, great video.

The flap thing is call a switch. great video

Great video, the little piece that closes the circuit is called bimetal probably stainless steel 😀

You have no Idea how much your knowledge helped me, thanks for a very thorough explanation. Have a great day!

Never thouht about that but you can see how important this electrical check is. Thanks man as it can such a great time saver.🤗

Straight to the GD point. Clear and concise. Thank you very much bro!

Relays that work of the cars computer may have a different voltage than 12 volts to the relay. Typically around 2, or 5. Not sure if giving 12 volts across the terminals will damage the windings in the realy.

Instead of over complaining about terminology used in this video, I think, if we have adequate knowledge of electric circuit, we should be more interested to analyze the circuit using correct model. For instance, if the coil has an inductance of 30 mH and a resistance of 150 ohm and the current needed to pull the contact is 50 mA after excited by the battery voltage of 12 V, we can predict or calculate the relay delay time until the switch is closed. To do this, we should obtain a complete response of a step function. In this case the battery voltage source can be modeled as a step function. A complete response = transient response + steady-state response. Alternatively, it can be considered as : natural response + forced response. Perhaps, there is anyone here who is interested in solving the problem I mention above. If so, give your answer. Please don't write the starting 1st order differential equation to be solved using either traditional method or Laplace transform method. Only write the final equation needed to obtain the result Just consider this as a refresher of our knowledge on RL circuit. For me, it is not as frustrating as when removing all of the wheel nuts or even the nuts on master cylinder. :) Cheers :)

I really liked the fact that resistance is discussed here, it seems to be often over looked in the diagnosis... I would prefer to test it while running to see if it differs under a load that the car provides...

Awesome job of explaining how to test a relay and driving home the point to check the resistance across the circuit!

@myRatchets

9 жыл бұрын

Sokhom Chhim np, yes checking resistance across the circuit is crucial. thanks for your comment.

That is cool. I just learned that if your horn works, you can swap your horn relay with the fuel pump relay and see if it starts if you're trying to diagnose a bad fuel pump relay. 🤙

Great video man, now it's time for me to try it..thank you....

THx, actually gave me a good ABC to on how to approach relay's Cheers from Denmark.

Want more videos please .this video was very good.

some relays are normally open and some are normally closed when no power is applied,..

Very nice, clear, clean and correct. Great job, thnx for taking the time to do this.

Summary: To test vehicle relays, connect 85 and 86 to 12 volt power source and listen for the click. While that part of the relay is still energized, test the now closed part of the circuit, the other two pins, and see if the resistance value is close to zero. If it's not, it indicates a bad relay.

2018 test a few relays thanks to this video.

i believe they now have solid state relays so there will not be a click. in both cases hook a multimeter / DVM to the circuit that will be completed 30 & 87. Put the DVM on ohms. before you energize the two contacts 85 & 86 for the solenoid, dvm on oms should read infinite resistance b/c the circuit is open. when 85 86 are energized, the DVM should go to zero or close to zero ohms.

Excellent job explaining and demonstrating how to test a 4-prong relay! Thanks.

@myRatchets

9 жыл бұрын

Joe Hall np, glad you liked it. cheers

Tbh you don’t get enough recognition my guy. Know your worth

The most helpful information about testing relay.

I feel confident after seeing your video that I can test relays THANK YOU!!!!

thanks, your demonstration worked for me. the only thing I was not clear on was the positive side connection, and I found that in a comment, well explained, herein. other question was does it have to be 12v power supply for a 12 volt system relay? reading comments, not really.

Exactly the video I was looking for. I need to buy a multimeter now.