73 Honda CB750 Custom Build Part 31 - Wiring Harness

you it's time for the wire harness welcome to hack a week yep finally at that point where we can put the wire harness on the bike and I've got a lot of prep to do before I throw that thing on there and I also want to explain a little bit about wire harnesses wiring and electricity for those of you out there that are little intimidated by tackling your electrical system on your motorcycle it's really not that hard you just need some basic understanding of how electricity works which will help you a whole lot with troubleshooting and a wiring diagram certainly helps a lot downloaded this one from the single overhead cam forums tons of information available on that site probably ought to put a link yeah down there I'll put a link in the video description to the forum and to the tech articles that are there but that's the wiring diagram for this bike so let's start out with a little explanation of electricity okay let's talk electricity how does it work well you know what the best analogy I have found to explain it is this water because it's a lot like water the way it flows through pipes the way electricity flows through wires it's very analogous to water so let's look at it like this let's pretend that we have a hill here's our hill here's the valley down here up here at the top of the hill we have a big reservoir of water okay gravity wants that water to flow down the hill it's going to pull it down the hill naturally that's that's gravity that's what it is well let's think of this as the source of our voltage okay or the battery let's just call this the battery and down here at the bottom this is the valley this is ground okay so this is around and appeared to battery this potential energy we have this is our positive voltage okay so if we were to put a little pipe coming out of the side of here and we had our water running out and flowing down the hill the force of gravity going down the hill is the equivalent of current flow through a wire this is a very very simplified explanation now so as this is flowing to ground along the way we can make it do work because of this flow this natural flow from the top of the hill to the bottom or the current flow of electricity from positive to negative so let's say we wanted to we wanted to run a motor well the equivalent of that would be a little waterwheel a paddle wheel and the current flows through or the water flowing down the hill will make the wheel spin around now suppose we want to turn a circuit on and off well we could put a little valve right here and the valve would basically stop the water from flowing when it's like turned off you know let's say that that's a switch and it would shut off the flow and if we bridge that and close that gap the flow can continue on down the hill so that's that's basically what's going on with electricity so if you've got a light bulb in there this is going through the light bulb we draw a little quickie light bulb there's our filament in there so the electricity comes in here goes through the filament down to here to ground and there's a resistance in there because there's nowhere for that energy to go other than heat so what happens is it heats up the element the filament inside the bulb and it glows and the reason it doesn't burn out is because there's a back inside the bulb so there's your basic analogy of how things work with electricity and when you're troubleshooting the first thing you want to make sure of is do you have a place for the electrical current to flow that place being ground so check all the ground wires first on Honda motorcycles usually my experience the green wires are ground the solid green wires are ground on those German cars it's brown wires American cars it's all over the place usually black but sometimes blue is sometimes - whatever but anyway check Browns first when you're doing some troubleshooting make sure you've got a voltage going from the battery to the device that you're troubleshooting of why it isn't working but always check grounds first because without that you're not going to have anything going on with any of your electrical devices it has to go from positive to negative okay end of lesson okay now that we have that little lesson out of the way and you know the basics of what's going on with electricity let's take a look at what we've got here that we're going to work on getting on the bike here's the harness here the main harness this is a new one and what I've noticed on these is that the tape that gets used is kind of cheap and the wrap is a little bit lacking it's yucky tape so what I usually do with it is at the end of these pigtails I'll wrap it up with some better quality tape and I swear by this stuff this is 3m super 33 plus really good electrical tape so I usually just wrap these ends on this stuff with a little bit of that tape just to make sure that they don't unravel later because they will this this kind of tape doesn't usually hold that well and here's all my other pieces of electrical that have to go in this let's see this is the front brake switch that's the lights that go to the instruments that's a ground cable there's the ignition switch brake switch this is the harness that goes to the alternator there's the clamps that holds the harness to the frame there's my wiring diagram here is the battery tray and main electrics mounting panel there's the fuse box right there there's three fuses that go in there this is the voltage regulator and that is an adjustable device we'll talk about that more later on this is the little safety unit for the starter so you can't start the bike when it's in gear over here is the rectifier the job of that is to take the AC voltage that comes from the alternator and turn it into DC voltage if you want to know a little bit more about rectifiers how they work check out that link right there and it'll be in the video description as well that's a little experiment I did with a stepper motor as a generator a couple of years ago and there's a good explanation in there about how a rectifier works this is the solenoid for the starter what a solenoid does is close as a switch inside here when it gets a voltage applied to it it's basically a coil of wire in there and then there's a there's a plunger that will move because the coil creates a magnet pulls on the plunger when it pulls the plunger it bridges a gap between these two big terminals on the top and then it allows voltage to come from the battery through this out here and go to the starter and it's triggered by let's see that little wire right there so when you push the starter button you're applying 12 volts so this wire energizes the solenoid closes the switch it allows voltage to go to the starter over here is a place where the signal light flasher would go I don't have one just gotta go get a simple round to Terminal one put it in there now this is the this is the old battery tray this is the new powder coated one and it's pieces that go with it and there's all the new rubber mounts and the strap for the battery this is all going to get installed on here transfer all of these components over to here and along the way we'll clean them up a little bit we can clean up the bolts etc I've got a bunch of extra parts to here in a box extra voltage regulators solenoids these are rectifiers possibly the owner was going to retrofit it with this type of rectifier I'm not sure but I've got one more sitting here let's see yeah I got one more stock one right there there's the horn there's an extra safety switch this is what's left of my switches left and right on the handlebars go over here and take a quick look right here is where the on/off for the headlight for the engine running and then the starter switch goes there over here is high low beam left right switch and the horn switch so none of the switches on the harnesses are are fully intact as you can see here this one's missing part of the switch and let's see this one here well there's the high/low beam switch there's the horn switch however the signal light switch doesn't have the other part to it or the plastic part so I did a little looking at eBay I found a left and a right switch assembly and with those I can pull the switches out and be able to use them on these or maybe just paint the ones that that I bought and put them on here because these are a little bit funky I really don't like that powder coat on these it adds too much to it there's a big gap right here on this one for some reason I cleaned it off and I don't know what's going on with that but I'll probably end up replacing both of those with the ones I bought Hey look what arrived just went out and checked the mailbox and my left hand switch I found on eBay for less than $30 has arrived good deal so I can pull for the parts I need out of this to make mine work right see it's got all the switches in it that's what I don't have awesome so as I mentioned before I'm going to put a little tape around the ends of all of these just to make sure that the existing tape does not unravel using my 3m stuff here before I get the wiring harness put on I'm going to change out the ignition coils I've got these dinah high-performance ignition coils that came with the bike when I bought it previous owner had these ready to go so I'm going to go ahead and get those mounted up first and some new plug wires so go ahead and put those on then we'll install the wire harness alright first remove old coils which means I'm going to pull the plug wires those out and then we got to get these screws off the mount points now we can pull the coils out here's the stock coil here's the Dyna coil the Dyna coils are three ohm says so right there and the stock tech coils measure 5 ohms as per the instructions here you can use the 3 ohm coil but you have to put a 1 to 2 ohm ballast resistor inline on the positive side to that the reason being is that way you don't have full voltage going to the coil and the coil will run really hot because it's only 3 ohms I know it seems a little odd but that's how it works out these are five these are three we're going to add a ballast resistor which should help them balance out - probably about 4 because this is going to be split between those two anyway we'll add that in later what we need to do right now is get the wires off from the stock coils and put them on to the new coils adding these terminals right here there's no polarity on these you could probably just decide that one side is going to be the side that goes to the points the other side gets the 12-volt feed there is a terminal right there at the tip of my finger I can unsolder that wire I can unsolder that wire and these coils are still usable then and I can take those two wires and put them on this coil and we'll be good to go to put this on the bike all right let's see you can D solder these wires there we go there's one got my two wires clipped got some heat-shrink tubing here I'm going to put a piece of heat shrink on to the wire ahead of time here and then we are going to put these connectors on to the wires this one's already got some solder on there we'll just go ahead and solver up this wire onto this connector so take a minute to get hot enough and remember when you're soldering you want to get the metal hot enough to melt the solder and you know you're going to get a good solder joint now we can slide this heat shrink tubing up here I can just use the soldering iron heat to shrink it you could also use a lighter or a match or a heat gun or a hairdryer I like to just use the soldering iron there we go I got a nice clean solder joint and a nice clean insulator around the connector got the wires all mounted up screws in place and we're going to put these back on the mounts now I'll put the plug wires in later because on this one they just push in with a connector on the end screws back in here make sure we get this little bracket that holds the wire in place okay one down one to go here's the drawing of the wire harness from the parts breakdown on the parts website I go to and we can see the harness right here we can identify some parts of it there's a bunch of connectors up here there's another little pigtail comes off there and then there's a third one there that's got a little square insulated connector on it so if we look at the harness itself we can pretty easily make that same identification there's the there's the one with the little plastic insulator on it so this would be the end that goes up into the headlight so we'll route that along this side of the steer tube and then the harness will run down through here and I looked and looked at pictures all over the place of where the harness runs some of them show it going through here some of them show it alongside the top tube here and then it gets strapped in place like right there and right there but I'm not sure just how I'm going to do that yet I think what I'll do is just kind of clamp it in place for now and such a way that I can see up here at the front I've got enough to go into my headlight bucket and then the rest this part just drops down through here so all of this mess needs to go down through there so I'll get these pods out of the way they're only temporary anyway not going to run pods or run stock filter so let's see let's just start a little at a time rotting them down through there and pull them out this end and we'll just leave it like that for now back to the battery holder now we need to take all these parts off from here and put them on here some of the parts are new as in rubber parts up here on the mounting part there is a little teeny spacer that goes into these rubber things we're going to pull those out and save them and we're going to put the new rubber bushings in here I'm going to use a little bit of the silicone dielectric grease tiny bit of that on each one of the rubber pieces helps them slide into the holes a little bit easier if you just get one lip started and give it a twist and then if you can hold it there with one hand take a flat blade screwdriver and start poking the other part through give it a little twist poke the next part through and voila it should just pop right in like that then we can push the metal insert into there and then the bolt that holds it will go in and it will bolt to the frame and it'll bottom out on that little spacer not on the rubber and then the rubber acts as an insulator for this whole assembly we have these other four rubber pieces that go in they are the bumpers for the battery they go in these four holes around the perimeter here same thing on these if you can get one part of it started through that little hole right there a little bit of that rubber nipple poked through first and then take a small flat blade screwdriver carefully poke it through the rest of the way a little bit of that silicone grease on there really helps you can see that it's poked through there and the other side where are we there it is mounted up all right all the rubber bits are in place now we can start taking this part all you need is a 10 millimeter socket eight millimeter socket because all of the stuff on here is either ten or eight millimeter so we're just going to start pulling these parts off everything is pulled off from the old bracket now we're going to test a few things I've got two rectifiers here and a rectifier is just basically four diodes and they're arranged like I mentioned earlier a bridge rectifier just go look up that stepper motor as a generator thingy on hack a week and you'll see a little more about that but we can test these pretty easily this main post right here is connected to this whole metal chassis that's the ground side of everything and what we're going to do is take this meter I have that has a diode tester function built-in and we're going to take the negative lead I'm going to connect that to the ground right here and now we're going to touch it on all these wires right here except for the green one the green one right there as I mentioned earlier green is ground on all these bikes so kind of hook that back up again okay so we're not going to touch the green I mean if I touch the green it's obviously going to be continuity it'll make a beep noise what we're going to do is touch it to all the other wires on here we're going to start with the red wire and that shows no continuity so what you're looking for is no continuity between that green wire or the ground of the chassis and all these other wires on the connector okay now we're going to switch it around the other way now I'm going to take my positive lead and I'm going to connect that to the ground here and now we'll go back and test everything again we'll start with the red wire and you can see we're reading about nine point nine seven three volts now we'll go to one of the yellow wires 0.5 volts the other yellow wire 0.5 volts and the other yellow wire 0.5 volts so that tells me that this is good what that all means is that the diodes are doing their job they're allowing current to flow one way but not the other way so this tests okay this is a good rectifier let's test out the starter solenoid make sure it's doing what it's supposed to do this big red lead right here well it's actually red underneath it all but there's a red stripe on it so one that goes to the positive side of the battery let's connect 12 volts positive for my little portable battery here same one I use to start the bike last week and now we have another lead that comes off from here that's connected to that same wire and what we're going to do is take the positive side of the voltmeter we're going to stick that on there I got the voltmeter by the way set to continuity so it'll beep when there's continuity across something now on the other terminal over here that's where the continuity should flow to so when this thing is energized if this is working right the 12 volts will go across here since I have that connected here if this is working properly we'll hear a beep on the tester when I ground this lead right here we're going to connect a little jumper wire to that because it's two recessed to grab it so let's see what we've got here you hear it click and you hear the beat so that means it's okay dead there we go everything mounted back up on the battery tray the voltage regulator we can test after the bike is running I have to have the bike running and voltage coming from the alternator going to the battery before we can test that but we will go over that later now we can mount this whole assembly to the frame okay here we go and drop all this stuff in here oh really are you uh are you me don't you just love like this I just realized that this has all got to be stuck in here before all these components go on um well you know what my alternative is to just loosen up the bolts for the oil tank and let it flap over this way a little bit darn okay oil tank loose that's better yeah just barely gonna make it a quick work of this and we'll do a final tighten up with a ratchet oh thank remounted now we can go over to this side and start connecting the wire harness all right so what we're after is to keep everything on that side of the frame these pods out of my way that is the battery let's see that's the starter cable that needs to route up to here I'm going to wait on that and let's see some of this stuff is going to be pretty self-explanatory I can only plug in one way so here's a red one red connector goes to the safety unit for the starter plug that one in make sure it goes all the way where the little safety catch hooks on to it fuse box whose box is going to be let's see six wires on it and this one has six wires let's go ahead and connect that one that's clicked into place what's next we got the rectifier that connects up right here and the wire color codes actually match up there's that and what else we've got a white yellow with a red stripe up here there's a yellow with a red stripe there's also a black and probably going to be over the top but for right now we're just going to connect them right here we'll worry about where it all routes a little bit better later on those are connected let's see now all this stuff I still got to figure out but that's a pretty damn good start not bad let's see I've got I got a harness that's over on the bench that goes from the alternator got to make a repair on that you know what I think that's about it for now everything I can do right here now I've still got this stuff up here to deal with the coils connect right here those are pretty straightforward all color-coded stuff and there's on this side blue wire that connects up right there and from the other side there's going to be that's for the one and two coil that takes care of the coils so we're going to stop there for this week I've got to get the headlight bucket mounted up because that's where a lot of things connect together up there for the front turn signals the headlight all this stuff right here I believe let's see this I think goes to the ignition switch there's some stuff I got to figure out you know but that's the basics it's going to run right down here it all goes down here onto all this stuff that's all connected now we got some things here to worry about later but that's gonna make it a wrap for this week hope you enjoyed that tune in next time and we will finish the wire harness up get things connected to the alternator and just maybe we can start it up and test the voltage regulator and it will move on from there so thanks for watching thanks for all the donations thanks for sharing the videos with other people and until next time we've got these other four that go in and they we have these other four rubber pieces that go in and they they need

Channel: HackaweekTV

Views: 127,057

Rating: 4.9008265 out of 5

Keywords: electronics, diy, hardware hacking, hackaweek, motorcycles, circuit, mechanical, wiring, wiring harness, cb750k3, cb750, honda cb750, coil, rectifier, solenoid, testing, component testing, electrical connection

Id: FooHVSSNgLA

Length: 29min 43sec (1783 seconds)

Published: Sun Feb 07 2016