How To Test a Relay The Easy Way

yo what is up you guys welcome back to the channel so today we're gonna do something different we're actually not gonna be working on a car but we are gonna be talking out a motive so what I'm gonna do today I actually had one of my subscribers comment on one of my last videos I think it was a fuel pump video where I was doing some checks on a relay circuit and he asked me if I could do a video on how it really works focus so I actually have a relay here this one's taken apart and we're gonna go over how it works what it does what it's good for how to check them how to test them how to talk butterfat and after this video you guys are gonna be able to do your own really testing you're gonna be able to bypass relays you're gonna be able to check if they're good or bad you're gonna be able to wire in extra circuits if you need to do that and I'm gonna show you all that in this video so let's go alright so check this out here we have a basic automotive really now for the most part every really has four terminals you have pin 30 and 87 whatever the big load is is gonna be on sites 30 and 87 now for the most part pin 30 is gonna be your your power side and then pin 87 will go out and feed the component that you're working with now pin 85 and 86 these are your control side this right here in 85 and 86 that is the coil pin 85 and 86 are what controls this coil right here so pin 85 for the most part is a power 86 is a ground but you can switch them around this is no problem all we need here we just need to activate the coil once this coil activates it creates a magnetic field and then this switch closes and then the power that's here on pin 30 will travel through go out to pin 87 and out to whatever you're controlling whether it's a fuel pump AC compressor a fan blower motor whatever it is so you can see that on the side of this relay that's what they're showing you here 85 and 86 there's a coil once magnetic field is created in here it pulls the switch it makes contact and then we have current flow from pin 3287 now if it doesn't have a diagram on the side of the relay it'll have numbers on the bottom of the pins I think you can see that this really on this style relay you see how these three are facing the same way how they are parallel with each other you can see that pin 30 85 and 86 are always gonna be parallel the one that comes perpendicular that's gonna be pin 87 this right here is 87 a in the middle and that's usually not used so anytime you see I really like this and for whatever reason it's not numbered or not marked on you for you then what you can do is know that these three facing the same way the two that are side by side those are your control side 85 and 86 and then the ones that are perpendicular to each other that's pin 30 and pin 87 pin 87 will always go to your load side which is a your pump your fan your light whatever you're controlling so if you ever need a jump a relay and bypass it you're gonna have to jump in 30 put a wire to it and to pin 87 at the at the relay box so one test you can do on the relay to make sure that it's working on the relay itself is resistance check across pin 85 and pin 86 so let me show you this really I'm good I got a couple relays here that I'm gonna show you just so you can see different resistance all right so the very first test you want to do is a resistance test of the coil to make sure that the coil is good now this is just bench testing the really this is not tasting the really on the car or testing the release circuit all right so the first thing these two pins are parallel and I remember that two parallel ones that are across from each other that is going to be our control side that is a coil so if we look at this one we've got about 72 ohms on that relay and this is a it says Prolink relay okay so that's one let's look at one from GM this one came out of a GM product so let's look at the terminals set it up like that the three that are parallel to each other will go across the two that are across from each other and we have we've got about eighty four ohms of resistance so that coil is intact there's no problems there actually we've got about 75 ohms okay now you should have resistance across that one you should not have resistance across pin 30 and 87 like I'm touching them here if you do have resistance across these two that means that that switch and there is stuck closed and this one is good that you shouldn't have resistance across these two until you have a power underground on this side which activates the coil which allows current to flow from pin 30 to pin 87 and out to whatever you're controlling so that's the second relay let me test this one this one is this is one that says dual tech electronics so set it down look at the three pins that are parallel and we go to the two that are across from each other and we have about 73 ohms now let's check the ones that are opposite spin thirty and eighty-seven okay I'm across spin thirty and 87 and I've got nothing now if I go across pin thirty and eighty seven eight I should have some kind of reading because this one has five pins and you can see on the ohmmeter I got about one or more resistance now you're here you are able to see that on the diagram here on the side the contacts across pin thirty and eighty-seven a 87a is a pin in the middle you can see that on the diagram that those that switch is touching the other one so you should have some kind of resistance there and you do so once that once this coil activates that switch will switch over to pin 87 and then we should have continuity between thirty and eighty-seven so now that we check the resistance of the coil on the relay we can actually energize it by adding power and ground to the terminal eighty-five two pins 85 and 86 and see if there really clicks so when there really clicks what you're actually seeing is these contacts being pulled in through magnetism and just because they're really clicks doesn't mean that they're really is actually good so first let me energized the relay and let me show you what that looks like so I got a I got a positive wire here and I got a negative wire here that are connected to a jumper box so I'm gonna connect these across terminal 85 and 86 of the relay so you should hear the relay click and you should be able to see the contacts moving all right so that doesn't necessarily mean that there really is good that just means that the coil is energizing the contacts are moving but we stuck out a check if there's continuity from pin 30 to pin 87 when there really is activated so I'm gonna set my digital multimeter over the continuity or you can set it on ohms either way and I'm gonna take one lead of the multimeter to pin 30 and the other one to pin 87 okay so that's pin 3987 that's a power feed and now I have a ground right here this so this ground is on the control side this one can be a computer it can be a module can be a switch it it's whatever it's controlling the ground for the control side of the relay so once I touch this here you should hear the relay click and you should hear my multimeter beep indicating that there's continuity between pin 30 and 87 and that indicates that this really is good so here we go so that's a test that you need to do on the bench with the really out of the car testing the really out of the car only tells you that there really is good it does not tell you anything else about the relay circuit about the control side of the circuit the low side of the circuit this just tells you that there really is good now it doesn't matter what kind of really use and you can use this style relay or you can use this style really this is another style of really that you're gonna be seeing now this is the one that you guys saw on my Hyundai Sonata fueling video this is the same style that was on there and if I can get you there Oh kiss now in this relay you're not gonna seep in 85 and 86 30 and 87 what you're gonna see here see if I can not hear it as you can see it on this one 3 & 5 are the equivalent of 30 and 87 so if you need a bypass to relay these tour of the control side these two are the load side and this one right here is the one that goes out to the load this one right here is gonna have a power feed then once there really activates that switch will close the power feed will run from pin 3 to pin 5 and out to whatever you're controlling essentially on the inside it's the same thing here's a coil you can see the switch right here okay now I'm gonna go ahead and activate it so that you can see what it looks like when you got a good power and a good ground on the relay so I'm gonna put a power here I'm gonna activate it by touching the ground to the other pin and you can see it activating okay so this really is good the coil is good is making contact but what you can really gotta check is if that power from from pin 5 is actually making out to pin 3 and out to your load essentially it's the same thing now this one came out of GM and you can see right here there's a diagram it shows you that pin 3 and 5 are the switch and pin 2 and one part of the coil side so every time you see a switch on a relay those are the pins that you're able to jump now you gotta be careful that you don't jump the wrong ones because whatever's controlling whatever is controlling that relay if you accidentally jump it then there's a good chance that you're gonna fry whether it be a module or a switch or whatever just go from the pin that's in the middle of the really the two that are on the top like if you look at this the pin that's in the middle that's gonna be your power feed and then you're able to jump into the one that's outside these two are outside on the outside of the relay so just know that these are your control side so that right there is how you test the relay that's how you read the outside of the box on a relay disk this one came from a GM car I think this was bad remember just because the relays clicking that means that this right here is closing but that something else could be wrong within the relay that's not allowing that current to flow and go out to whatever your your load that you're trying to control is so there it is that's pain three and five that you can jump while you're working on the car alright guys so that's how you test a really on the bench it's a completely different test than testing it on the car on the car you're gonna have to check the control side the load side but that's how that's how you do it out of the car so you have to understand the basics before you can go test it on the car and hopefully you guys like what you saw in this video hopefully you guys like what you saw in this video and if you did don't forget it leave me a like if you want to see something else drop it in the comments the reason I did this video was because one of my subs actually asked me to do this for him how the relay works and what not so pretty simple it's just two circuits inside a little box once the control ones the load side one controls the other it's a small current controlling the higher current very very important to know how this works on a lot of newer cars they're starting to get rid of these and they're starting to build the relays into the circuit boards into the modules and and those type of cars these relays are not serviceable but it's still the same it's still the same concept so hopefully you guys liked it leave me a comment down below what else you want to see and I'll make it happen for you guys now there there will be a part two to this video I'm gonna show you guys how to test this on the car and how to check the relay circuits at the relay box and that's it that's it for this one guys I'll see you guys on the next one peace [Music]

Channel: Homie Hektor

Views: 1,981,382

Keywords: how to tell if your relay is bad, how to check relays to make sure they work, how does a relay work, what does a relay do, basics of an automotive relay, easy way to diagnose a faulty relay, how to bypass a relay, como chequear un relevador, como trabaja un relevador de carro, como eliminar un relay, como diagnosticar un relevador facilmente

Id: ieyr63wDqG0

Length: 13min 0sec (780 seconds)

Published: Sun Mar 10 2019