Basic Automotive Relay Operation and Simple Wiring

Basic Automotive Relay Operation and Simple Wiring


alright guys this one this video is going to be based on relays and basic wiring of lights or horns basically whatever you want to put on your your Jeep or car or whatever this is basically just a simple explanation of how to incorporate a relay into your wiring which could be good for a lot of reasons which I’ll explain in a little bit first let’s look at a relay this is a basic example of a relay right here what you’re going to have here is your four poles of which some of them have five and I’ll explain that in just a second which would be right in the center there which is the 87a your first one is going to be your 85 which is your ground and the 85 and the 86 are going to be basically your trigger circuit now what a relay does is it’s just a bridge for a higher power circuit which we’ve all heard of like a starter solenoid that’s because the starter can draw over a hundred amps when it’s cranking a motor and if you just ran that through your ignition switch you would easily fry the wires so use the solenoid and a solenoid is basically just a stronger version of this relay and obviously it looks different but it does the same thing so you’re 85 and you’re 80 that’s going to be what tells the switch to close for your bigger circuit now typically you’re going to run your 85 to your ground and your 86 is going to go to your power so basically tear your switch source that you can run with thinner wires into your dash instead of running you know your 14 gauge wire you know that you may need for your accessory depending on the amperage that ik draws your other prongs here 30 and 87 are going to be free or actual intellectual accessory now xxx is going to be you know they’re labeled here I’m saying all these numbers but if you look on the relay they’re labeled or sometimes I have a diagram like this and the xxx is going to be where your 12 volt supply comes in typically you’re going to want to fuse that with something like a 15 amp fuse or you know just under what the what the relay is capable of supporting and this can apply to fans lights horns you know whatever the 87 is going to be your output so once this trigger wire once you flip your switch it’s going to connect this it’s going to bridge the 32 the 87 and then you’re going to have 12 bolts right here and that’s going to turn on your lights now the 87 a five prong one which isn’t very common but if you do need it or if you do want to use one for any situation this is basically where the 30 the power from the 30 terminal is going to go until you switch it on then it will transfer to the 87 and take it off the 87 a here I’ve drawn a simple diagram to go through let’s say we have these two lights right here now you’ve got these mounted on your bumper or whatever you’ve got two wires a positive and a negative which with a light you know the polarity doesn’t really matter but we know that we need power and we need ground so the universal symbol for ground is is lines like this and if you were to mount these on your bumper say you ground the one wire to your bumper assuming that it’s to your chassis without rust or her powder coat or something else that would basically prevent it from having a good droned then we’ve got our battery over here naturally unless you’re starting with a whole brand new vehicle it’s already going to be grounded from the factory for all the other electronics on it so for our relay we need a thirty to have an input so we’re going to give it 12 volts from the battery and then let’s say we mounted this switch here on the dash okay we know that the switch is going to need a power because it works with 85 85 and 86 work together and that needs to make a complete circuit so say you’re 85 we’re going to run to ground and that means we need power on this side so if we’ve got power from we can either do it you know from the battery or say you want it ignition on you can go to something like your fuse box your fuse block excuse me with like the accessory outlet or the cigarette lighter and you can put that you know in line with that circuit so that it’s only ignition on that this works if you don’t want your lights to be able to be on or your fan to be on if your key isn’t in you can wire to that and so this could be ignition on only so now we’ve got our 12 volts and with Ettrick John is going to complete the circuit here which will essentially close this path here now we’ve got our 12 volts coming in from the battery and going through a fuse and now we just need somewhere for this to go now if you’re not familiar with series versus parallel circuits you know either either check that out on the website or check out the other videos and there’s an explanation of that but we’ve got the grounds on the lights and we’re going to need a power so if you were to splice these together we can run the power right out to these two lights now the difference between the series and parallel just really quickly basically if you ran you know these two lights in series it would be like this so basically you have your 12 volts positive and negative this is a horrible drawing I’m sorry but they’re in line with each other so let’s say if this light bulb right here burns out this is going to take out the whole circuit that’s a serious circuit there’s also different aspects of it as far as the amperage and the current draw but like I said that’s in a different video so for now what we’re going to do is we’re going to do a parallel circuit and this is going to ensure that if this light bulb goes out this one still works and they will both get their 12 volts there won’t be a voltage drop so they’re both going to be just as bright as the other one like I said this is a very simple explanation of it if there’s any questions feel free to submit them on the Facebook page or send me an email and stay tuned for more videos thanks for watching but you


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