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.

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

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

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.

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

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

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

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..

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.

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

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

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

Best explanation ever . Thanks a lot

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.

Excellent info and great explanation!!! Thank you!

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

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

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!

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

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

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

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.

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.

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!!!

Best video on relays I have seen yet. ❤l

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

very good demonstration, made me understand, great guy!

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

Thanks for de info 👍🏻grts from Belgium

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

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

Excellent video. You are a great teacher.

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

Excellent informative video thanks

Very thorough! Thanks so much!

thank you for your video it been a big help

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

Thenk you for the video is helpful God bless you.

Good Testing！ Very helpful for me

Great video, informative on to work with relays.

thanks so much, that was valuable information

Great video on electrical relays

Thank you for the video, exelent.

Great information 😊

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

Super helpful ! Thanks..

Excellent, excellent video.

Great job 👍

Thank you a great video

Awesome thanks 🙏

great job ....... thank you

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?

Well explained..

Good job.

Thanks so much.

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

great thank you

Great video

Amazing thanks a lot.

U saved me today like thank u

Awesome presentation! Question? Where did you get the leads for the 12 volt? Thank you.

What is the acceptable resistance rating on a Wehrla 21164-12 volt Part #911.615.108.01. Mine is reading 60.7?

Thanks

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

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

I tested the 4 pin glow plug relay 103 of my car, the resistance is 64 ohms. Does it mean that the relay is bad? Need to be replaced?

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

Nice vid!

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?

thanks

Thanks!

Yeah man great video

I have a 97 Camry fan 4 pin relay Bosch. Has no 87 but listed as 87a? It seems to be working when tested with a multi-meter and 12 volt source but my relay testers is saying its bad.

Nice video. Nissan horn not working. Good fuses and 12v on one blade plug. I tapped on horn relay and got it to work for a split second. Then nothing. Then the horn worked shortly thereafter for 1 night. I've got a 3-blade Nissan horn relay. I can energize two blades and it clicks, but only in one direction. When I energize the two blades with a good 9v battery I measure about 4v on the output blade that goes to the horn. The 4v steadily decreases if I hold it on the 3rd blade and monitor it. How do I confirm the relay is the issue? Thanks!

trying to fix my fog lights in my car they are aftermarket/oem. i know I need bulbs but why did both blow out at once?

hi i need help i have a 1984 cheverolet p32 and the 5pin relay in your video is same as the one i have i looked at the wires the red goes to 30 and to the fuse box and white ground goes to 85 and green goes to 86 to neutral safty switch there was a yellow wire on 87 but was just cut 4 inches up i bought a new relay do i need another wire for this to work im not very good with electrical but im trying my best to get it running its a nice truck im trying to restore so any input would be greatly appreciated

Thank you sir

... if one has a out of production relay, could one just pigtail a more common 85/86 relay?

Keep thanks

My Opel astra G 1.6 16v 2003 keep stalling even when I drive! Relay keep clicking when ignition is On! Could be the relays problem?

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

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.

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

THANKS

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.

I use a power probe. And I am good with it. Can you explain some ways I could use a multimeter that may be better than power probe. I debating on buying a multimeter. Everything you did in this video I can do with power probe. But I feel like I need a multimeter. But what would I do with it if I had it. What can a multimeter do that the power probe cant

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.

😮🎉😮🎉😮🎉---😊, 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 KZfaqr 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.

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

Thanks for the help i have been trying to find out how to test my fuel pump relay on my 94 Chevy c1500 2wd 5.7L. i had a check engine code 54 to pop up and when I looked it up there was two different things that could be causing this code one was the fuel pump relay ( low voltage) or it could be a he EGR valve solenoid. Hopefully i can find out how to test the EGR valve solenoid hopefully it is something simple. But knowing my luck ( I ain't even going to say it, don't want to jinx myself ) but again I want to say thanks for your help)

what if the 4 pin relay has nothing on it !,can power a pin to see if it clicks ? and i power the wrong one would it burn the coil in it ??

What if your not getting system voltage out of 87 after it is energised?

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.

where'd you get that auto meter i need to get one for my brother im a plant maintenance technician but he's a tree surgeon and i need to find a meter like that for him

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😮

What about Relay with DIOD and how check pollarity of it ?

So when i send power through 86red and 85blk I have continuity with both 87a and 87.

Best of all relays testing material videos on youtube so for I found, appreciation is a must. Also I have a question if could answer me would greatly be appreciated. I was testing my honda pgm fi 4p relay. Ignition on, I see 12v on switch side pin #86,87, and load side # 30 but on pin 87 it was 0.16v. What can be the reason it the relay is not closing the circuit properly? Although bench test was ok. My car has crank no start issue. Thank you

👍🏽🇺🇸👍🏽 very helpful

What about if brake lights stays on as I’m driving. I disconnect brake light switch and lights stays on