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Discussion Starter #1
Hello all,

Recently bought a '89 'm 750 which was in parts including the wiring harness removed. I was told she was running prior to being stripped down.

My question is; what is required to run this bike electrical/wiring wise and what do i need to get there?.

I've bench tested the starter which is good, but I surmise I need to at least bypass the ignition and bypass to get spark to the spark plugs?.

What would be the simplest way of accomplishing this?. Id be okay running my own wire from the positive terminal to whatever is needed just to temporarily get the engine running.
 

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NewB to Vulcans
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Does the bike still have the electrical accessories mounted? Junction Box, Ignition system etc etc?

If so power the ignition system directly and crank away. There are wiring diagrams published on here showing the connections
 

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Discussion Starter #3
Hey thanks for getting back to me. There are no accessories. No gauges, ignition switch, shut off switch, lights, ECT.

I have looked over a few wiring diagrams. Maybe you can confirm if my initial plan is on the right track:

1). Wire new switch controlling the starter.

2). Wire a switch from the battery which sends power to the ignition coils.

^ if I did both of these would the engine be sufficiently wired to, in theory, run?.

Thanks again!
 

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Hey thanks for getting back to me. There are no accessories. No gauges, ignition switch, shut off switch, lights, ECT.

I have looked over a few wiring diagrams. Maybe you can confirm if my initial plan is on the right track:

1). Wire new switch controlling the starter.

2). Wire a switch from the battery which sends power to the ignition coils.

^ if I did both of these would the engine be sufficiently wired to, in theory, run?.

Thanks again!
CDI has to get power and needs wired to the rest of the ignition components.
 

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Ditto on what Spockster said. Pretty much every wire on the CDI needs to be properly connected (or for pin 5, be connected to ground instead of the JB if the JB is MIA to think it's connected properly)

If the wiring (CDI/JB) is in-tact except for the stuff on the handlebars, then you can just put constant voltage on the red wire (ignition) and wire a button for the starter wire (black).

If your R/R is still connected to the stator, make sure the monitor wire is connected to v+. Probably better to leave it completely disconnected in the initial phase if wiring has been messed with around the junction box.
 

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Discussion Starter #6
THANK YOU GENTS! I feel like I am very close to understanding this now. Just a few more questions (promise)

I've taken a few pictures of the harness. The part in confused about / want to clarify before frying the junction box is: how do i run constant power to it as you guys directed?
 

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Discussion Starter #7
I guess I am just failing to see where i need to run the wire from the battery to power the JB and then, from which JB wire to hook up to the coils. (I realize I'm showcasing my ignorance, but really want to make this project work). Thanks again
 

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2003 Vulcan 750/Sidecar
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Uh, maybe someone else can bullseye which wires are the right ones, but there's supposed to be a short but beefy length of wire with an eye that bolts onto the positive battery terminal, and that wire runs to one of the big terminals of the starter solenoid (which you currently have plugged on to the molex connector for the R/R) and attaches via a spark-plug boot looking thing. That boot should have a second, much smaller wire (white/red) running out of it, through a bullet connector, and then into the wiring harness which eventually connects in to the junction box as a white/red wire on pin 1.

I'm squinting really hard, but I don't see either of the wires that should hook on to the starter solenoid. It's possible those are still attached to the battery/frame? disconnected from the harness at the bullet connector?
 

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I will add the connector with 3 yellow wires in a row (total of 6 wires in connector) is the connector for the R/R. its dont hook to the starter solenoid (it looks like its connected in the last pic, but may just be placement of the items)

also, I see 1 coil, there are 2 coils. each coil with 2 spark plug wires (2 plugs per cylinder, 2 cylinders, 4 plug wires total)

also, do you have the CDI box? it has electronic ignition, and that box is required.
 

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The hot wire from your start button can run to the spade terminal on the starter solenoid.

Is your goal just to get it running, or to make it roadworthy? You're going to need a fuse box and connections for lights, and a control circuit for the fan.
 

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2003 Vulcan 750/Sidecar
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I have a question aside from electrical. In your second post you say "There are no accessories. No gauges, ignition switch, shut off switch, lights, ECT."

Are these not mounted or did they not come in the boxes? Do you have the hand control assemblies? IE, throttle, clutch?
 

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Discussion Starter #13 (Edited)
Thanks again for all the replies gents. I have zero doubt without you guys heloing that this would be yet one other "never go anywhere projects".

I only want/ need to get the motor running. I am not looking/needing it road worthy.

Sorry, I do have the other ignition coil,just didn't not picture it. I have no other accessories whatsoever.

I do have the starter solenoid and the main positive wire which runs from the pos batt terminal. I also have the small wire which goes with it and plugs into the JB.
 

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I do have the starter solenoid and the wire which runs to it from the pos battery terminal, BUT no associated small wire which as you said should run to the JB.

So given what we've talked about, I feel like I am (kind of) close be being able to run this thing?.
You said you had a switch to use as a start button? Just run one side of that switch to the spade terminal on the starter solenoid.
 

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Discussion Starter #15
So following Thorn's insight, ;

*Run a main from pos battery terminal to starter solenoid,

*run (or locate) small wire to connect from starter solenoid terminal to #1 pin in junction box,

*???? Then connect the ignition coils to the two small connecting wires from the harness and run direct hot wire from the positive Bart terminal as shown in the "coil bypass" mod thread????.

I owe you all a (few) beer after this.
 

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Discussion Starter #16
So in moving forward;

*connect main positive from battery to ignition.

*connect small red/white wire (pictured in previous post) to wire harness red/white wire which runs to JB.

*connect ignition coils with x2 small wire connections from wire harness AND main wire bypass as outlined I. 'Ignition coil bypass mod' thread.

* then???? In theory all required electrical hooked up to run engine?
 

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Sounding good.

Make sure you've got a good ground from the frame to the negative battery terminal too.

Michiganteddybear asked some good questions. I don't see a CDI box in your photos either. Absolutely needed. And a second ignition coil.

Spockster mentioned the spade terminals on the starter solenoid. You'll need to take a wire from v+, through a switch/button, to spade, then from the other spade to ground. Not sure which wires go to which terminals. Post back if you can't find that info.
 

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Discussion Starter #18
Okay; last piece of the puzzle guys. I have the cdi box from the guy I got the bike from.

Took pictures (see attached). Is the last step running leads from the cdi box bare terminals to the coils? Or am I missing a hook up which should be clipped in the bare terminals?
 

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on the igniter box. that is the wrong connector plugged into it. that connector is for the R/R.. and not needed to just see if the engine will run.

I am going to say (dont quote me, I may be wrong here) that in order to start it, you need to feed the igniter box with 12V, GND, 2 pickup coil signals (2 wires each), and the outputs to the ignition coils. there is another input that is active when the start button is pushed, but we do not know exactly what it does, but theories are it may adjust the timing during starting.

on the engine, the pickup coils are behind the cover on left side of engine where the stator is. there should be wires from the stator (3 yellow ones), and 4 wires from the 2 pickup coils exiting from the top of the left side engine cover.
 

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Solid thumbs up to what MTB said.
The best way to deal with the CDI box is to plug in the proper 6-wire connector from the wiring harness (dark green, red, black, red/white, black/yellow, black/white), and a 4-wire connector from the pickup coils (not part of the harness. black/yellow, black, black/red, black/white). The harness should have connectors on it that hook up directly to the ignition coils (two red, which can go to either coil's positive, a black, and a dark green for the two negatives, which need to go to the proper front/back coils).
Once those are all hooked up, the battery hookup as previously mentioned should work as intended.

I think the ignition coil mod linked to earlier would leave the red wires disconnected from the coils, and would jump power more directly from the battery terminal. Might not be worth messing with when trying to fire up the very first time. The more wires you chop when you don't know exactly what's what, the more difficult things will be for you down the road.
 
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