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What is the best wiring diagram for a 1979 xs650 special?

Discussion in 'The Garage' started by Ricky_F, Oct 13, 2020.

  1. Raymond

    Raymond XS650 rider, fettler, setting out on a journey XS650.com Supporter Top Contributor

    Ricky, with due respect, time to think not buy something. Did you say the r/h flashers are working? If so, there is a wiring issue on the left. Buying a new relay or some diodes will not fix it. Most wiring problems are due to poor earth connections.

    In logical terms - a physicist would tell a different story that is not relevant here - current flows from battery +ve via the fuse box to each component and then back through the frame to battery -ve to complete a circuit. Bad earths are common. For example, an earth to the handlebar or headlamp shell should not be trusted because the whole front end of the bike is only connected by the steering bearings - a set of ball bearings in grease - giving a poor/intermittent connection

    The black from your battery -ve goes to a bolt on the frame. You need to check the resistance from the wire leaving the turn signal switch to this battery earth, with the switch pushed to left. You probably need the switch unit opened up to touch your multimeter probe on the bare wire. Resistance should be nearly zero. Check again at the wire entering the front flasher and the rear flasher. Anywhere the resistance is high tells you which area has a bad earth or a broken connection. I really would like to see you fix this but you will only solve the issue or issues with hands on the bike and thinking it through logically. You will never solve it by rushing out and buying something. IMHO.
    Last edited: Oct 20, 2020
    Ricky_F and 650Skull like this.
  2. Ricky_F

    Ricky_F XS650 Enthusiast

    I have spent the last almost two weeks messing with these signals. The right side was working fine before but only when I had LEDs only in the back. Now I have LEDs in the front and back. They only stay on constantly. I've been reading a lot of solutions to people's LED problems and also watching videos. That's why I now say that diodes would solve my problem.

    I need the current to only travel one way when I hit the signal. Putting diodes from the flashers to the harness wire and grounding the rest will certainly solve my problem. I've have ruled out a faulty switch and faulty everything else. Except maybe a two prong electrical relay or the diodes which are cheap and easy to insert. I didnt take any shortcuts. I have been trying to do this for awhile and came to this conclusion. Tomorrow I will also try to run a long wire from the battery -ve to my headlight bucket and see if that can make a difference since it will be a really strong ground. I'm taking in eveyrhing I'm being told. LEDs on these old bikes are a trip.
  3. Ricky_F

    Ricky_F XS650 Enthusiast

    This is what I mean by diodes by the way Screenshot_20201020-040859_Chrome.jpg

    It's one of a couple solutions since I dont have an indicator bulb
  4. itschrisb

    itschrisb XS650 Addict

    Again I’ll say it even though it is not the popular opinion. Just wire your own signals. Bypass the mess of an original harness and just do it yourself. You’re basically fighting a slow leak by filling it with air everyday expecting it to stop leaking. The wiring on the bike IS the problem. You need signals to ride your bike to work. At this point you could have wired it 5x over. We are talking about bypassing a mess of 40yr old wires to make a much more reliable system so you can ride your bike. If you have LED bulbs and an LED flasher with new wires your problem is fixed it’s literally that easy. I don’t know why everyone seems so determined to get you to continue doing tests on an obviously broken system. But hey your bike.
    Ricky_F likes this.
  5. 5twins

    5twins XS650 Guru Top Contributor

    There should already be a ground wire to the frame running through your harness up into the headlight. It usually gets connected to one of the coil mounts .....


    Make sure it's clean and tight.
    Raymond and Ricky_F like this.
  6. Ricky_F

    Ricky_F XS650 Enthusiast

    I will check this wire Twins, thank you. I also now can hook another ground there if I have to.
  7. Ricky_F

    Ricky_F XS650 Enthusiast

    Chris, how would you bypass everything to make your own signal wiring? Any advice would help. Right now what I do is I manually make my left or right flashers flash by turning the switch to the direction I want and then off again. O'Reilly's had no diodes so I'll have to check auto zone tomorrow.

    I have the flasher and the lights would I need anything else to make my own signal wiring?
  8. itschrisb

    itschrisb XS650 Addict

    Find your ignition switch and figure out which wire has 12v when you switch the key to ON, if it’s the oem switch it should be brown. Splice a wire into that wire and run it to your flasher relay. Run a wire from your flasher relay into the handle bar turn signal switch. From there you just need to run wires from the handle bar switch to the front lights and wires to the rear lights. Try to use different colored wires so you know what is what. 16awg wire is good enough. It’s really pretty easy. Mount the flasher unit pretty much anywhere that makes sense, the oem bracket would be my first choice but it doesn’t really matter.

    *edit* excuse my extremely crude drawing but this should give you an idea of what you need to lay out.

    Attached Files:

    Ricky_F likes this.
  9. Ricky_F

    Ricky_F XS650 Enthusiast

    I've never seen such a bad drawing be so accurate and easy to read haha. Thanks man! I'll do that and when I get a new harness from DAddy in a few weeks I can wire the new one in or just leave it like this.
  10. 650Skull

    650Skull SSSSSSSSSlither Top Contributor

    I'v tried...........posted 2 versions of the indicator circuit from the ignition switch to the indicators on their own

    Now your over the moon of a rough pencil drawing.........

    You will get there i'm sure..........
    gggGary, Raymond and itschrisb like this.
  11. itschrisb

    itschrisb XS650 Addict

    If someone can’t understand a wiring diagram and how it translates to the motorcycle then it doesn’t matter how many times or versions you post it. He needed to see how it applies to his bike and that’s exactly what I showed him. My drawing shows just how simple wiring is. Your schematics just continue to imply that wiring is difficult because it’s just a bunch of color lines running around in a grid. I’m not saying it’s a bad thing, it’s useful when trying to figure out what’s what but it doesn’t help much when you’re trying to see how those wires are physically laid out on the bike itself.

    moral of the story: there is more than one way to skin a cat.
    gggGary likes this.
  12. 650Skull

    650Skull SSSSSSSSSlither Top Contributor

    Yea your right..............these are so difficult to understand............ because they are a bunch of wires running around in a grid................

    Post #10..Page 1........................Post # 78.......Page 4

    Moral of the story............read what has been posted and work together not in different paths
    Last edited: Oct 21, 2020
    Raymond likes this.
  13. itschrisb

    itschrisb XS650 Addict

    you’re being difficult for the sake of being difficult. Those diagrams don’t show physical locations of anything in relation to the bike. None of them do, so yes it is difficult for some people to wrap their head around. It’s the same reason why watching a video is sometimes easier to understand than reading words. Again there is more than one way to skin a cat.
  14. 650Skull

    650Skull SSSSSSSSSlither Top Contributor

    On these circuit diagram with the ledgers of the components..........

    If someone cant find the where the parts are, and relate them to the bike, they need to ask a question....................... the other question they should ask them selves, are they the right person to be doing this sort of work?

    I don't know how Socrates survived without Utube
  15. Brassneck

    Brassneck XS650 Guru

    Hey Ricky! Welcome to the madness, and kudos for jumping into the deep end. I've been reading up on this thread, and boy there's a lot going on here. Your bike is interesting...I think the only things that are stock are the frame, motor, and maybe the side covers. Nonetheless, it can all be fixed...and your enthusiasm is fun to watch. :)

    I won't muddy the waters with any advise that hasn't already been said. But I think the turn-signal discussion is really a good allegory for your project. The system itself is relatively simple...but needs to be taken step by step or things get sideways quickly. Some of that is description/word choices along with various pictures and assumptions made and some of that is based on timing, posting and reposting, actions and results-- all of which on a forum can feel chaotic. :)

    Personally, I was a bit confused by the right side signals being "on" and the left being "dim"... and then add a 4 prong relay into the mix complicates it further. I'm not a flasher relay expert, but I think in general, a 2 prong relay simply sends a pulsing current to the switch (At the handlebars), whereas a 3 prong does what a 2 prong does but also sends an independent signal to a dash light...and a four prong is probably automotive and maybe has a hazard light option? Nevertheless...with a flasher installed, turning the handlebar switch to the right side should light up the right side bulbs...if they are in line with the flasher and the flasher is correct for the style of bulb and load put on it, they should flash. If they don't flash, then the flasher relay may not be appropriate for the application (It may need a load put on it for the 3rd ad 4th prong, for example--or all the lights need to be connected for it to work correctly, like in the stock relay, etc). OR, the flasher isn't in line with the turn signals... Again, not sure...but you may want to get a 2 prong flasher to eliminate that possibility. Then trace the wires to and from the flasher, and then to the switch and then to the turn signals. And draw out the colors, how they route, where they connect for yourself--essentially creating your own made wiring diagram for the turn signals. Once you know all the wires are in circuit, power and ground wires are secure and the flasher is correct for the application, you will have completely understood the wiring for the turn signals and you'll know exactly where the issue is.

    Good luck!
    Ricky_F, Raymond and itschrisb like this.
  16. Ricky_F

    Ricky_F XS650 Enthusiast

    Thank you for this long breakdown! I ordered a new switch that comes today and I will follow this thread to make sure I do everything correctly. I also have to go grab a two prong electrical flasher now that my switch is here. I will let you all know how it goes. If it doesn't flash then I will take the making my own wiring path!
    Brassneck likes this.
  17. Ricky_F

    Ricky_F XS650 Enthusiast

    Hi guys, I was wondering if any of you could direct me to where I could acquire some new carbs? My right one was leaking, when I cleaned it a piece of the float bowl(where the screw goes into) broke off. They were worn anyways. I tried to find some for sale posts on here to no avail. My current ones are 32mm XS performance carbs. Not sure if they are stock
  18. Machine

    Machine Race the wind Top Contributor

    78-79's were originally equipped with Mikuni BS-38 mm CV type carbs. Try posting a "wanted" titled ad in the classified section.
    Ricky_F likes this.
  19. Ricky_F

    Ricky_F XS650 Enthusiast

    Thank you, I will do that.

    Also if my current bike has 32s would I have to order the same size as my current ones? Didnt see that mentioned anywhere. I know bigger is more power, usually.
  20. Machine

    Machine Race the wind Top Contributor

    The intake manifolds may have also been switched to accommodate the Mikes XS 32's? You'll have to determine that and go with what you can find. I source mostly locally because there are plenty of XS parts ads if you reach out , you can likely find options.

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