How do I learn electrical systems?

Discussion in 'The Garage' started by Swashbuckler, Oct 21, 2013.

  1. Swashbuckler

    Swashbuckler Been here awhile

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    Currently trying to build/restore/fix a crf450x into a do it all bike. I'm almost done, but am running into problems with the wiring. The problem is that I don't know a single thing about wires, diagrams, or how any of it works. I'm not looking for help, rather I'm looking for anyone who knows a book, guide, or manual that will help me understand the electrical system. Something as simple as installing a keyed ignition with only 4 wires terrifies the hell out of me, and it's completely unacceptable. I just don't want to be posting questions, and endlessly searching the web for every issue.

    So is there a book you read that would help me understand the electrical system?
    #1
  2. aposaric

    aposaric Garden mechanic ;-)

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    #2
  3. Swashbuckler

    Swashbuckler Been here awhile

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    Thanks, but i've already read both of those articles and many more.

    To give yall an idea of what I'm looking for - when I bought my new Nikon D7000 I also picked up an 800 page book that helped me learn the camera front to back. I could have went online and read every one page article available, but I prefer having a nice book to turn to that has most of the answers i'm looking for.

    I know - this is a strange request in todays world where most people can barely focus enough attention on one article on the internet, let alone a whole book lol.
    #3
  4. yokesman

    yokesman Been here awhile

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    To be safe use your battery charger set at 2amps for testing,electrical basically point to point. you will probably find it easier if you mark your schematic at each connection as you trace the switches on the schematic ,if not available use c colored pencil for claroity
    etc.ie the ignition switch:
    on- connects to various other systems and relays, trace that out, maybe make a chart with the connections being noted. start-to the interlocks(which you may want to disarm but before you do be model wise) start motor etc
    if you do this before you start,by the time it is all done your understanding will have been to a point where you are ready to begin the connections. tie them when finished as close to the connections to keep the stress off them,separate- protect them from vibration and chaffing with additional looms.
    dan mc online training will help here also. the owners manual has some info on switch positions and the related lights and switch positions needed ie kill to on,clutch in,stand up.
    #4
  5. k-moe

    k-moe Long timer

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    #5
  6. RedRaptor22

    RedRaptor22 Been here awhile

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    One of my biggest breakthroughs with electrical work was when my neighbor who is an electrician told me not to think about it all as wire and electricity, but like water and pipes...suddenly everything made tons more sense to me and seemed a lot less scary lol.
    #6
  7. sailah

    sailah Lampin' it

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    You have basic tools like a nice multimeter?

    Sitting down with a VERY clear wiring schematic, and using a fine pointer, start at the battery and start following along. Wiring is very logical. Once you learn the various symbols (there aren't many on a bike) AND what they do, it all starts to click.

    Start with a basic wiring diagram like how to wire up driving lights.

    Does this make sense? If not, what specifically? I think if you can take small steps in understanding the big picture will happen quickly.

    [​IMG]

    Once you figure out the various circuits, you can break them down into reasonable sections and isolate them. Just looking at a full schematic without understanding smaller blocks of it is intimidating.
    #7
  8. anonny

    anonny What could go wrong?

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    Hmmm...... is it me or does that headlight not really have a 12v + feed, I just don't see the yellow wire picking up the + side of the battery. :huh

    Or is terminal 85 feed internally?
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  9. Donkey Hotey

    Donkey Hotey De Jo Momma

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    Neither. I'm pretty sure that diagram is showing how to connect a set of driving / fog lamps to the bike, using a relay and a switch. It's connected to the hot side of the headlamp so they only work with the low beam.
    #9
  10. Swashbuckler

    Swashbuckler Been here awhile

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    I have no tools. But I do plan on picking up a voltage meter and crimpers.

    That diagram does make sense on how power travels from the battery to each light and out to a ground. But everything in-between the battery and the lights is more than I know.

    Here's my situation as of right now.
    First: I just wired in a tusk street legal kit to my crf. It was a simple plug and play off the battery. But I need to find out how to cut the wires to the headlights and attach them to the tusk wiring harness. It's simple, as there's 3 wires connecting the lights, and 3 wires coming from the tusk harness. I just need to figure out which ones are which. But I'm still lost on how to do this.

    Second: The PO placed a pressure sensor on the rear brake to turn the rear running light into a brake light. He spliced into the factory wiring harness. My new tusk pressure brake runs right into the tusk wiring harness so it was easy to complete. But now I have the old brake wiring hanging out and I want to put it back to factory, and am unable to figure out which wires were factory and which weren't.

    Third: I picked up a keyed ignition switch. Nothing fancy and it's purely a thief deterrent. I just want to connect it to my start switch which is only 2 wires. The keyed ignition has 4 wires coming from it. I don't know if I only use 2 of the wires, or 2 in and 2 out.

    Fourth: I bought heated grips, and they've been sitting in my garage for over a year. I have no idea how to install these. I'd also like to see if I can provide enough power to power the grips, gps, and maybe cellphone.

    I'd like to start out by wiring the headlights and eventually learning enough to set up my own "control panel" for my gadgets.
    #10
  11. gatorgrizz27

    gatorgrizz27 Been here awhile

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    If you are doing something custom and not following a diagram, you just have to understand how it all works, luckily it is pretty simple. It helps to separate things out and tackle them one at a time.

    First, everything besides a switch will need a ground, whether it is a wire, or self-grounded by mounting it to metal. Grounds are typically black wires. Power just needs to be delivered at the right time, either with the ignition switch or through a separate switch like the headlight. A test light is your friend for finding power, use a multimeter to figure out switches.

    Cut the headlight wires and make sure they aren't touching anything that will short them out. Put the headlight switch on low and test the wires for power with the key on, some bikes need the engine running. One of the three wires will have power, the other two won't. Now switch it to high, the wire you found before will no longer have power, but another one will. That is your high beam, the one left is the ground.
    #11
  12. Swashbuckler

    Swashbuckler Been here awhile

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    I've read that I cannot ground wires to my aluminum frame. Does this mean that all my wires run power from the positive battery terminal throughout the bike and back out of the negative terminal?
    #12
  13. D.T.

    D.T. Difficult but useful

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    I like the factory service manuals, especially the Suzuki ones.

    Looks like you are doing a custom job though. So just read everything you can and these web sites are great for learning the "tricks" that the nOObs don't know.
    #13
  14. sailah

    sailah Lampin' it

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    They might not all run back independently, piled up with ring terminals. And they probably don't. Most likely the grounds are crimped together along the way, or use a buss block, and then routed back to the negative terminal using a thicker wire to carry the amps. But all the grounds need to get back to the negative terminal somehow. Can't comment on the aluminum frame thing. I know aluminum conducts electricity, just not sure how well. Often electrical problems are due to poor grounds which is why it might not be the recommended grounding method vs copper wire
    #14
  15. Stan_R80/7

    Stan_R80/7 Beastly Gnarly

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    I am not sure there is a book to show how to understand an electrical system. There are books on general principles of electricity. But they most often describe principles and not specifics. Having the service manual with the correct wiring diagram is needed to understand any electrical system.

    Thinking of voltage as pressure and current as flow in a piping system is an excellent analogy for DC (direct current) electricity. Figuring out the colors in a wiring diagram, locating the correct wiring and components, then being able to measure voltages (and sometimes currents) will allow troubleshooting most any vehicle electrical system. A multimeter is needed.

    The reason some makes state to run separate wiring back to the battery for accessory ground is because the frame is made of aluminum and steel. The ground current will travel through the frame and dissimilar metal locations can corrode because of the current - which then causes a failure. Also, the ground wire or grounding has the same electrical importance as the positive wire.

    The best advice I can give is: figure out how to read a wiring diagram (schematic) for the system you are interested in learning. Once you can decipher the color coding, routing of wire, and components, the measurements (via a multimeter) and sorting of why something does not work becomes much easier. Also, figuring out why something works or doesn't from a wiring diagram helps prevent damage to the motorcycle. Some simple problems like a dead battery or that a switch is now in pieces on the floor can be easy to spot, but for most anything else a wiring diagram is needed.

    Good luck!
    #15
  16. Swashbuckler

    Swashbuckler Been here awhile

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    So from what i've been reading. My new wiring harness is built to power the headlight. I can disconnect the headlight from the factory harness and wire it to the new tusk harness. This will leave me an open power source from the factory harness that I could use to power my heated grips and gps? Should I take this source and connect it to something like this http://www.fuzeblocks.com? Then I can run my gps and heated grips off of the fuzeblock?
    #16
  17. flemsmith

    flemsmith lurk

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    The problem with asking us specifics on components we aren't familiar with is, frankly, most of us are too lazy to do the research it would take to give you an expert answer.

    I was trained as a EE, and when I wire a bike, or make changes to a bike's wiring to add accessories, the only way I can do it confidently is to first draw my own schematic with proper wire colors, component connections and functions, (like that relay in the light circuit above) and in some cases wire sizes. I'm seldom able to just look at a factory schematic and follow what I need, because there are so many other things going on.

    E=IR. Using a multimeter should lead you to understanding that. Voltage = current x resistance. In DC circuits, you don't typically have to worry about frequency, inductors, capacitors, or complex impedances, so it's much easier than analyzing an AC circuit. But you do have to understand the difference between those three things and how to measure each. There are books, trouble is, most of us no longer have any basic DC theory books. When people talk about poor grounds, they are really saying the resistance back to the battery with a remote ground connection is too high, so the current is too low. Sorry if I'm not much help, but it's really a learning process.
    #17
  18. LittleRedToyota

    LittleRedToyota Yinzer

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    just so people don't get unnecessarily confused, the statement on that page that "All power for all systems on a motorcycle comes directly from the battery. The alternator is only used to charge the battery and prevent it from becoming depleted during normal use." is not true on many bikes.

    on many bikes a lot of stuff is powered directly by the alternator/stator (and uses AC rather than DC).
    #18
  19. TeneRay

    TeneRay 2>4

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    If you're trying to learn on what I'm trying to learn, then this is a pretty good book.

    I took an entry course in electronics and circuits while in college but that was ages ago. Sold the books due to finances. I found this in B&N for $40. I read one of those Dummy books prior to this one and that was junk.

    Usually I'll follow up a questionable issue on YouTube to help explain the subject. Works so far.
    #19
  20. troidus

    troidus Long timer

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    One other piece is whether the alternator has sufficient output to handle all of the proposed loads. You may wire everything correctly and still run the battery flat.
    #20