How To Test and Diagnose Relays and Wiring [4 & 5 Pin]

[@thegrave2000]

Finally someone who explains in detail how relays work and how to test them. Thanks a lot, appreciate it!

[@markiefufu]

I'm glad I ran across your video. I tried watching other videos and reading how-tos. None of them made sense to me as they weren't explaining how the relay works. They were only showing how to test with whatever relay they had on hand. It didn't help at all. After your video, I can test my relays in seconds and now that's I know how they work I'll never forget this how.

[@jctedsap]

My thoughts exactly! Have played with automotive electrical for decades and never understood relays. Not anymore.

[@teenice894]

Ive been wrenching for 10yrs and been avoiding electrical testing. Time to take it head on as I'm doing lots of repairs as a side job for extra income. Once i master my diagnosis skills my price is going up!

[@tmo2798]

Let's call it a 'consultation'.

[@tonya6915]

Some one said, why he talks so much. If you really want to learn something. Then listen to the whole thing. Anyway I loved the video. Now I know how to check relays. Thank you so much for your time.

[@ramindadseresht4074]

You can even use a flat 9 volt battery and perform the tests. It worked for me. Excellent video man👍

[@artis813]

This was a great and simple explanation of how relays works and how to troubleshoot if the relay is good. Thanks. Keep it up.

[@DuelistMandroid]

Best relay testing video on the internet!❤ Thanks for sharing this.

[@Shoptoolreviews]

Wow, thank you! That's why we do it. Thanks for watching.

[@dancin4]

Relays and solenoids are considered high current switches a lot of people are unaware of this. Yes the control side 85/86 is switched by the computer most times in an automotive application. Great video and I love that meter.

[@s.j.5850]

Good basic information on how a relay works. Thanks for showing the Kaweets multimeter, it's the first time I'm seeing it. Look forward to more of your videos.

[@jamdc2000]

This video goes straight into favourites, thanks Tim, and take care.

[@Shoptoolreviews]

That’s great to hear. Thanks for watching

[@wiretamer5710]

Watch half a dozen of these, and yours is the one that worked for me. Thank you.

[@energy102]

The best and most complete explanation I've seen. Thank you.

[@edwardpurcell2905]

This actually sense to me now. I still have questions and some confusion as to why a relay works for a short period then stops. However I now can begin going back through my system

[@josephbragg1162]

Great video. I was looking into buying a new multimeter and this new one with chargeable battery and the auto feature looks amazing and only being 40 something dollars on Amazon is a great buy. Thank you. I'm buying one now.

[@markyakubovsky3380]

Great stuff man.. Thx!! I am sitting here at my desk with my fluke and power supply feeling like an absolute Genius thanks to you..

[@tombryant7955]

I didn't have a 12-volt battery so I used a 12v battery tender for power. It performed both tests perfectly without worrying about damaging the relays.

[@nicholasscurti8001]

I had a little understanding of relays, when I tried to add fog/driving lights on my '72 Toyota Corolla & a little background in electronics. However, I never completely understood what the numbers stood for & exactly which terminals did what, even though I successfully wired the lights. Now, as an old guy, you helped really understand. Thanks!!!

[@markiefufu]

I'm in the exact same situation. Took electronic classes in HS and learned more in the army. Being in my late 50s, I am finally a pro with relays. Lol.

[@fixityourself5713]

I been wanting to learn the process and this was an excellent video. Thanks!

[@kleenmaint]

Thanks. You explained the 87a which the other videos didn't make as clear. I ordered a repair manual. I hope the wiring diagrams are helpful. Getting prepped so when my starter doesn't turn over next time I can see if bypassing the relay will work and start to narrow down my problem.

[@alfredoverno9674]

Sir, YOU make this video easy to watch. your teaching mannerisms are most helpful. thank you for breaking it down to my level. great stuff. I subbed based on this video.

[@theroastbeefking]

So glad i found this video. I finally understand how relays work. Thank you

[@jontnoneya3404]

This was really cool - I would love to see more about this. Specifically how you walk through a real problem when it's not some major component like a relay or a fuse. I'm dealing with a fuel pump that's not working. Motorcycle sat for 8 years with fuel in the tank so I knew I needed to replace it. Since I was already in the tank, I replaced everything previously in the tank....the fuel pump, pressure regulator, fuel filter, float sending unit, all fuel hoses, wiring harness. Now the problem is when I turn on the ignition, the pump still doesn't sound. I added 2 gal of gas and still nothing. I even made a long hook so I could manually change the float sending unit and the level on the fuel gauge didn't change. SO I'm thinking it's not getting any power to the pump. Fuses were fine - I checked the continuity and they're great. Changed both relays cuz they're old and cheap....still nothing. NOW I'm going to have to test the voltage at the relay and walk it forward but I don't know exactly how to do that. I'm also thinking I should check the plug on the outside of the tank that delivers power inside the tank. However I tried doing that but I'm honestly not sure if what I'm seeing is what it should be. It's confusing when you've never done this stuff.

[@bobbyg4100]

Excellent Video, great explanation of Relay functions. Love the test board and your Stainless Table to write on . Great Camera angle also 🙏God Bless You.

[@abdirahmanhabib398]

This is just superb. Well explained nothing unnecessary and to the point. Thanks.

[@joeellison-z2n]

Great video, I always knew what a relay did just didn’t know how it did it Thanks for talking in layman’s terms.

[@topeka409]

Diagnostic question maybe answered from this video. I had clicking lights in the interior and windshield wipers. They drained my battery. I am going to try this now! Thanks for the great video. Easy to understand

[@louisroman7134]

Thanks for sharing, it's helping get out of the rabbit hole.

[@kordellsouthall7805]

Appreciate the video. This is what I struggle with at school. I understand it now.

[@SparkyGentle1]

Thanks!

[@Shoptoolreviews]

You bet! Glad we could help. Thanks for watching and thanks for gift.

[@laskeysikazwe1770]

Wow, professionally explained and quite informative 👏👏👏👏

[@hittz8331]

Great video guys. I learned alot and got more understanding on the subject. Thanks Much

[@ThunderbirdRocket]

Super helpful ! Extraordinary detail !! I learned lots !!! Thanks mate !!!!

[@victormendoza6306]

Loved this video show something how easy it is to test relay before replacing in a wrong way

[@jeffcantley9203]

Very nice presentation with model straight to the point an extremely easy to understand thank you so much.

[@StormitheTC]

This was a great video. Thank you. I’m wondering…can you then reverse and remove a component from this? If it’s a 5 prong feeding a faulty antitheft system preventing a vehicle from starting, can we eliminate the system and put a four prong to bypass?

[@AlvinDelaPaz-ni3jd]

Thank you so much for the clear and easy tutorial.

[@pitchforkpeasant6219]

Awesome video! Amazing how such a simple thing doesnt have such easy to understand videos such as yours👍👍

[@MikeyMack303]

Thank you. That was a very good demonstration of those types of relays.

[@seanmiller8507]

Great video! Smart and thorough! 5 star rating and thumbs up!

[@fix135]

My only quibble is that it's not a resistor between 85 and 86, it's a coil that, when energized, creates the magnetic field to pull the relay switch to close the 87 and 30 contacts.

[@bernardocisneros4402]

Some relays have a resistor across 85 and 86 to mitigate the destroying effects of a back EMF spike. Some relays even use diodes instead of resistors

[@benniedonald]

Best video on relays I have seen yet. ❤l

[@danielcookeb90]

Great video my friend. Well put. Maybe some more specific examples as used in the switching process' in the car would really embed the learning. Knowing there is a high and low side is key, but how they interact in the different automotive situations ( indicators, pumps, etc ) exactly wouldbegreat, but maybe that video would be too long! Super video, I'm ordering the crocodile clips!

[@martymcmannis6581]

Great job letting us know about them explanation went a long ways Thanks a lot

[@zimway57]

Can I just use a spare 12 volt mower battery with some alligator clip wires to energize the relay while testing? Do I risk damaging relay? GREAT video and explanation

[@BeldenTopo]

Love this explanation ❤️💯 Very clear

[@apolomauai7890]

very good demonstration, made me understand, great guy!

[@meirzeevi3618]

Best explanation ever . Thanks a lot

[@samuelbrooks7854]

thank you for your video it been a big help

[@johnnielewis9896]

thanks a lot...and the key is infrequently review and/or practice this application in order to retain it... peace

[@debbied5607]

Very thorough, Great video. What does it mean when the 87a across 30 open and giving numbers jumping up to 6.7? Does this mean that it’s a bad relay?

[@moturcu4226]

100% clear explanation.

[@rcclassiccrawlers4368]

Stumbled upon your channel. Very cool episode, learned something I’ve always wanted to know about. Thanks a bunch! Subscribed!!

[@tapiwachikandamina1550]

Helpful, thanks for that vedio

[@WarriorsPhoto]

Amazing video. 😊 Electrical on cars is simple. At least the basics are. 😊😂😊

[@lasorelay]

Good Testing！ Very helpful for me

[@robburdine5429]

Helpful but you did not include anything on the last relay type the thin rectangular one. The one I needed that has no numbers marked next to the pins. So I cannot figure out how to check.Any suggestions on what kind of video might have that. What type of relay should I search for? Again helpful but never got to the last one. Shown but not mentioned or discussed so I am clueless on how to fix. If you can please advise. Thank you.

[@Paul-ns8fr]

He said if the prongs line up its 85 and 86 the other prongs are the 85 and 30 the 85 86 are the low side the 85 and 30 are the load side.

[@Photoshop.Expertise]

AWESOME VIDEO!👍🏽🇺🇲 AND THE MOST HELPFUL IN EXCELLENT DETAILS! 👌🏽🇲🇽 YOU EVEN BOTHER TO GIVE US ADVICE AND LINKS ABOUT MULTIMETER THANKS A LOT MAN! 🇲🇽🤜🏽💥🤛🏼🇺🇲

[@CamrynPratt-v9l]

Excellent informative video thanks. Excellent info and great explanation!!! Thank you!.

[@Edward135i]

I'd say most ECU's would use grounds to control the relays, that's how all of the aftermarket ones i've used worked to control the fuel injection for instance because they aren't designed to have high amps passing through them.

[@fryefamilyband]

Very thorough! Thanks so much!

[@theprofessor5584]

Great video on electrical relays

[@mmdouble7674]

😮🎉😮🎉😮🎉---😊, WOW! Thank you so much for taking the time to make this video too inform me about the routes electricity takes when ground/12 volt / 85/87A/420/69 etc .. ..... .. . My experiments haven't been as fulfilling as I know they were many moons ago. Installing these relay switches inside of the cranium of two species of saltwater fish. I could not get the wiring correct from the electrical brain diodes running to the tail then to the relay fuse and of course it grounded to a hollow bone in the jaw. Then wired to the fins, and from the fins to the 12 volt battery installed exterior of the scales. I couldn't tell you how many salmon I use for practice and I had very neat effects/ movements on command, forward left right and even reverse. It isn't a very good backup job reversing for the fish but it tries even though it doesn't know what it's doing. sounds out of the voice box ( fish don't have specialized vocal cords or larynx's so the most popular way is through a tribulation, the same way crickets makes sounds the fish rubs two phones together or clicks producing audible 112 decibels mimicking music or songs that are being played through underwater sonar speakers. And of course all the tones are in the range of the eardrum that the earthworm grows naturally.. But everybody knows that. (The unnatural eardrums have never worked going back to 19 63 when Klaus Schmidt revolutionized the hearing aid affects/quality for the endangered scouts that were trapped inside of the cave during the mining accident in Mexico. I digress 🤔 I lost my concentration where was I..... Oh yeah! So I got the huge fish wired up with the relay on the interior of the cranium with the 12 volt battery that is securely placed on the dorsal fin. With no holes or anything drilled into the fish because the last thing I would want to hurt would be the beautiful beautiful experimental fish. If anybody would be interested in the conclusion of the first round after this kind KZbinr gentleman taught us all about relays, I'm happy too provide my link to the science paper that is peer-reviewed by my peers at the institute.

[@JulioSerrano-hr6sz]

Thenk you for the video is helpful God bless you.

[@davymoose3815]

I GET IT ! B/C If your relay is good there might be a problem somewhere else !!!? THANK YOU !!

[@blacksapphire5864]

Can we not use the no 30 when using it for auxiliary light just to supply only the no. 87? Like I'm connecting the 85 to ignition switch and 86 is in the negative? And let the no 30 and 87a alone.

[@bernardocisneros4402]

No, because terminal 30 is what provides power.

[@konstantin-big]

​@@bernardocisneros4402 You can connect 85 to a switch so you can turn on the light 86 you can connect to ground 30 you can connect to B+ battery 87 you can connect to auxiliary light

[@bernardocisneros4402]

@@konstantin-big But they don't want to use 30 and 87. Why use a relay if you're not going to use 30 and 87. You're better off using a butt connector and just using the ignition switch. You should always connect 85 to ground and 86 to positive side of control circuit. It will work the other way but it's technically incorrect. The next mechanic will assume 85 is connected to ground because that's what the standard says.

[@konstantin-big]

@@bernardocisneros4402 I am a car electrician I have been in the profession since 1974 If you use a relay then you haven't Voltage drop, and you can use a small switch to energize the relay

[@bernardocisneros4402]

@@konstantin-big If you've been a car electrician since 1974, then you should know why 85 should be connected to ground and 86 should be the switched terminal. I understand how to use a relay and the why and when to use it. I don't think you understood blacksapphire's question. Using a relay doesn't eliminate voltage drop it only reduces it. You're using a low current circuit to control a higher current circuit. It cuts down on using larger diameter wires but instead of only having one fused circuit, you'll have 2. One for the control side and one for the load side. Not only have I used relays but I've also designed them.

[@jalton9416]

Excellent video. You are a great teacher.

[@Shoptoolreviews]

Glad it was helpful!

[@anthonycollins9984]

Because of the way you explained how to test a 4 pin and5 pin relay, I believe that I will be able to test a few relays on my 1999 GMC Sierra truck. I noticed that you used a 12 volt battery with two short wires plugged into it. Where can I get a battery and the two short wire pieces from? I see that I can get the set of wire leads with the alligator ends attached from amazon.

[@tomt9543]

Between 85 & 86 you refer to it as a resistor. It’s actually an electromagnetic coil that pulls or releases the pivoting contact point, right? I’m sure has resistance, but it’s not a resistor in typical electronics terms. Great vid though!

[@bernardocisneros4402]

See the answer I gave to @fix135 above. In addition to that, a coil is made of of loops of wire and wire has resistance, so technically it's also a resistor.

[@effdeeash]

Thanks for this video, with your help I think I just found the reason for my car not starting. 🎉

[@Shoptoolreviews]

Great to hear! That's why we do it. Thanks for sharing.

[@Nicole-dj3jf]

Question my battery cable end keeps coming loose alternator changed funs fine for a month then bam everything dies battery was 13 when started alternator shows 15 amps im getting so upset paying all these people to fix my car the battery end is not the normal ends that most vars have please help 2011 3.6 chevy Malibu ltz any help please

[@konstantin-big]

@@Nicole-dj3jf Hey Did you find the solution on your problem????

[@RobertMattison-pp6uf]

Great video, informative on to work with relays.

[@djnagl]

Absolutely appreciate your explanation and hard work. I have a question that no one has been able to answer for me. I have a 20A fuel pump fuse that blows as soon as I hit my push/start button of which obviously doesn't allow me to start my car. I replace the fuse and as long as I don't try to start my car it doesn't blow, giving me the chance to check my plugs that go to my fuel pump module and the actual plug for my fuel pump under my back seat. I have power running to both plugs, continuity is fine and my fuse is still good so where is the fault at in this situation thanks in advance?

[@woodyifhecould4024]

Starter short?

[@Freda-s4g]

Filter is clogged. Pump should be pulling 10 amp max

[@dawsondemontiney1247]

awesome video sir!

[@HotRod4God72]

Great Video 😊. Im checking a random no start with a single click in a old 96 Toyota Camry. Can a relay switch sometimes work and sometimes not? Any information would be greatly appreciated. Thank you.

[@bernardocisneros4402]

Yes, it's called intermittent operation. It could be the start relay, the starter solenoid, damaged wiring, dirty or corroded battery terminals, corroded wiring, or bad ground etc.

[@konstantin-big]

I think you haven't relay in that car Maybe that clicking is coming from starter??? Then you need an electrician

[@HotRod4God72]

@konstantin-big ty buddy. I fixed this back in July...It was indeed the starter.

[@konstantin-big]

@@HotRod4God72 Ok

[@jamesmasona4234]

thanks so much for valuable information my car can now start, it was showing all those symptoms

[@rileyandikeysplaytime5936]

What about 87 & 87a "normally open & normally closed" like having an illuminated indicator lamp on when an accessory is in the off position? That's how I understood the difference between 4 and 5 pin relays.

[@thesetruths1404]

This works sometimes: bang on relay. I had a horn relay that would not work. So I disconnected battery. Tugged, poked, whacked and shook relay. Would not come out. Read it had to be replaced with whole relay tray, or cut out. Hooked up battery to call it a night and presto it worked. I guess it was just stuck with a little corrosion. If does it again I'll drill 3 tiny holes in the top and spray silicone spray into relay to possibly fix corrosion issue for long time.

[@angelgomez7917]

Nice! For us who enjoy mechanics but not so much electronic

[@justanother67camaro32]

Go to test power across 85/86 and pop, smoke, awesome!!! Going to guess that's complete junk now. Thanks👍🏻

[@michaelcrawford7354]

I have this 5-pin relay that operates the electric chute deflector up and down on my Kubota snow blower. It is located under the hood but for some reason I keep getting water in the relay case and shorting the relay and causing parasitic drain on the battery. Any suggestions on how to eliminate the moisture in the relay case? It has me baffled because this is the only relay that has this problem. TIA

[@bernardocisneros4402]

If water is getting in terminals 85,86,87, and 30, you can pack that with dielectric grease. If water is getting inside the coil housing, then apply RTV around the seam between the coil housing and relay body.

[@konstantin-big]

You can change the position of the relay so that water does not enter the relay

[@mikebren11]

Outstanding, well done!

[@seus1985]

Thank you sir for the help

[@Shoptoolreviews]

You're very welcome. Glad we could help. Thanks for watching.

[@MikeSmith-xg5zt]

Great video!!! Very informive!!

[@atheplummer]

Hmm. I've got relays that don't have 87. It has 87A, but not 87. I'm figuring out that this relay is on all the time, but when the control side is activated, it turns off. It is a 4 pin relay. The part # is FOOCLE FLS820-012-1B. There are absolutely zero that show up on a google search. The 1A & 1C show up, but not the 1B. Ironically, the others are 5 pin. On the front of the relay, there is a white tag that says: Red 12V DC White Relay control Yellow Pump A Blue Pump B I'm trying to use this relay to control a coil to a plug, for a Plasma spark ignition demonstration. I'm using a 12V DC LED strobe light controller to energize the relay, to simulate breaker points to fire a spark plug. This one is a head scratcher.

[@OscarGarcia-sk8px]

I am testing a 1733 5 prong relay. I measured the 85 tp 86 and it measured 74. In the video you said it should be 75 to 100. DOes that mean my relay is bad? My other test showed OL. I did not test with power since I did not have a power source handy. Thank you

[@thewomble]

Pity the link to Amazon for the multi-meter says unavailable. A very good video explaining relays.

[@antonioanghelescu4666]

I tried to verify my headlight motorcycle relay everything was good until i tried to power it with a 12v parkside battery, when i touched the terminals with the wires it shorted… was the relay bad or did i do something wrong I put a wire to 86 on relay and - on battery and another wire on 85 relay and + battery

[@bernardocisneros4402]

You did everything right. Just a coincidence. Unless it was a 6 volt rated relay.

[@antonioanghelescu4666]

@@bernardocisneros4402 thank you for your reply, it wasn’t a 6 volt relay, i took it off my motorcycle, i guess i am just lucky :)

[@JoseHernandez-lf6cr]

Great information 😊

[@Shoptoolreviews]

Thank you

[@lightbright8888]

Excellent info and great explanation!!! Thank you!

[@frederiklansu270]

Thanks for de info 👍🏻grts from Belgium

[@craigpadley3535]

Thanks Buddy that's helped me a lot 👍

[@DieselMike]

Excellent, excellent video.

[@DouglasMorgen]

Man you break it down so well. Thank you.. okay but check this out I got high on PCP and took a hammer to my ignition fuct off everything my ignition signal sticks, basically smashed out everything from the steering wheel to the tilt lever. I'm left with a bare steering column a wiring harness for my ignition switch with one red wire in a cluster of wires what's a clip. Thankfully the clip is intact and I believe that's to my ignition switch. But I got to get the hell out of here so how do I start my car. I can send you a picture that's what I'm dealing with if it makes it easier for you to help me with s*** please help😮

[@Hoodozhnik1978]

Wow... Thank you! Amazing video

[@brianhickman9816]

Great video. Thank you

[@JlLj-pp2ni]

Great video...questi9n. So if there is power at 87a and 87 when powered that's a problem? Correct

[@glasshalffull2930]

Sounds like it might have failed inside and has fused the two circuits together. Pull the relay and ‘without power’ test to see if you have continuity between 30 and 87a and then 30 and 87. If BOTH have continuity, then they are somehow fused together and it is broken.

[@olatundeabiri7048]

Great video! May I get to know the model of your multimeter?

[@jamesmasona4234]

thanks so much, that was valuable information

[@Goodellsam]

Does that mean if you are using a 5 pin relay, you could use it for hi and low beam headlights?

[@konstantin-big]

You can use that relay for hi low beam headlights Brought must know how you can connect 85 and 86 pin

[@mikev.1034]

85 & 86 is the coil. That operates the relay.

[@philliphall5198]

One of them has to be grounded for it to work eather as a power source or a ground source

[@dinoquintana4319]

Excellent informative video thanks

[@DenisHuaHin]

I have been trying to find out what should be a simple question, everyone talks about primary and secondary. my Honda Coils has two spade connections one is blue/ green the other is black which one is primary? And what wire connects to it, live or signal.