[Markak]

Tested the pick up coils since I was getting no spark. Test the 4 pin connector while spinning the motor with a 12v test light...I got no hot light out of any of the connector pins. Is it possible for both pick up coils to go bad....

 

[michiganteddybear]

with the coils disconnected, you may not be able to measure anything comming out of them. they are magnetic pickups.

I believe they send a fairly low voltage signal to the ignitor. and its pulsed, with a very short pulse duration.

I dont think they are biased by the igniter (putting a voltage on one side of them and monitering the other leg).

best way to check them would be with an oscilloscope if I am thinking properly on their operation.

you can use ohm (resistance) measurements to check them, and there is a spec in the manual as to what they should read

 

[Thorn]

Yeah, you're not going to light a 12v light from those leads. The resistance should be 355 - 535 ohms.

 

[RoadHopper]

... and as they get old and cook, they become brittle and easy to break, so BE CAREFUL. Test the ohms before and after your job.

 

[Markak]

Well I spent most of the day looking for anything, I test the pick up coils (455 Ohms) after I did the pick coil MOD, then I tested the ignition coils (1.9 Ohms), ignition coils have power going to them (tested) but still zero spark going to the plugs. Im lost now, electrical gremlin! Any help would be greatly appreciated,

Mark

 

[Spockster]

Found this fairly confusing diagram showing the IC Ignitor box wiring. Maybe someone can figure it out.

I was trying to find how the IC Ign. is powered from the junction box. Looks like maybe the red/white wire, but the diagram has me befuddled right now. Think that red/white just branches off the start circuit, discussed in the Two-Wire Mod sticky thread.

Or you may have a dead IC Ign. box.

 

[RoadHopper]

Found this fairly confusing diagram showing the IC Ignitor box wiring. Maybe someone can figure it out.

I was trying to find how the IC Ign. is powered from the junction box. Looks like maybe the red/white wire, but the diagram has me befuddled right now. Think that red/white just branches off the start circuit, discussed in the Two-Wire Mod sticky thread.

Or you may have a dead IC Ign. box.

That'd be my guess, but i'ma too much a n00b to say so. Nice diagram... i'll give it a study.

 

[RoadHopper]

Okay, pretty straight forward and agrees with the other wiring stuff that is more or less accepted around here... ( see Thorn's master copy of the colors that go everywhere . . . )

The heart is basically the flywheel... and the pickups sense a weak field spike which is fed to the IC Ignitor. The IC stands for "Integrated Circuit" which in essence means it's not going to get fixed, and they ain't gunna tell ya what's in it...

... but... what is in it is two things, and possible both are the same ( which they probably are since it's cheaper to design than kludge ). There will be an amplifier/signal shaping circuit inside, basically a transistor and it only needs one, but they probably have four to provide various things like stability, regulation, and other kewlies wave shaping things that keep the circuit "safe". So... in essence, you can think of the IC as just yet another relay, but it's just special because the weak little guitar pickups down there by the wheel, get amplified just the same as an electrical guitar but... with a fuzz-box, ( seriously ) because they probably want a square wave hitting those coils ( just a guess ). The square wave has the hysteresis characteristics to give that coil a "time shaped charge" ( so you get good fire, fast, exactly when they want it, no sooner, no later then POOF, off in a flash. The coils are fed by the battery but only after it goes through the stop switch and the ignition switch ( the key ). In essence, the key and the kill switch do exactly the same thing, in opposite tandem. The JB doesn't do jack squat as far as the coils go.


Been up awhile, about ready to crash, so... obviously i stand corrected in advance. Hope this helps.

 

[Markak]

RoadHopper,
Thanks for the info, I will check the ignition out today, is there a way to test it and you said theres a kill switch as well?

 

[OleDirtyDoc]

http://www.vn750.com/forum/showthread.php?t=18475
Try reading this.I am looking at more old posts will post more linky thingies later

 

[Markak]

Thanks Brother, I really appreciate it!!!

 

[RoadHopper]

RoadHopper,
Thanks for the info, I will check the ignition out today, is there a way to test it and you said theres a kill switch as well?

Spockster's diagram above is a roadmap for exactly that. To test the entire thing, if it were me, be meticulous and stupid. What i mean by that is that usually it's faster to go through every step of an electrical system and make sure each part is in working shape, than it is to try and find "THE" problem. It's a better method for two reasons: Firstly, when something fails, many times it fails simply because it's old. Insulation dries up over the years just like tires wear down. Rubbing, pulling, changes in temperature from hot to cold every night and day will eventually make copper and plastic lose their connectivity between each other, and... to top it off, at different rates. So the odds of a wire failing due to age at one spot in a system of unknown quality are pretty low. Add to all of the above, that working on a system in the first place "disturbs" it since the technician is pulling in places that are normally not pulled, and moving things around to get other things out of the way. So, instead of hunting for "THE" problem, its usually better to presume there is more than one problem. Statistics are in your favor then. Secondly, even if "THE" problem is found, the typical reaction is to jump up and down, yell, "HOORAH!", jump on the bike, and get a six pack at the store. Need to test the bike then anyways, right? right. The odds of it running the same as usual then are poor because of the reasons above. So then the technician, who had the opportunity earlier to test every single wire is faced with the "square tuit" of needing to pull out the test equipment again and pull the various parts off the bike to perform more hunting, all the while a little frustration has dampered the "Hoorah". If one part of the system has failed due to age, the odds are high that another part of the system will fail for the exact same age reason very soon.

Testing a wire is a three step affair. Test it has continuity with an ohm-meter or a simple LED and a battery. Just prove that one end carries electricity to the other by passing a little through the wire. The wire then has two more ends. Cleaning the contacts on both ends is the job. Disconnect each end, use a little spray and a wire brush while inspecting each end for exposed metal that could touch something else. Make sure that each end has a physical connection tension so that besides being clean, the two sides of the connection can actually touch, touch firm, and remain that way during rattling. In that process, then, remove any oil that seeped into the connector, or any insects, leaves, corrosion from fluid spills, etc. The bike lives in a harsh electrical environment, and uses cheap connections ( relative to consumer TV/computers ) that use little if any solder.

The left side of the system, i explained above for the most part. The right hand of the system introduces the several ways that the bike uses the junction box to defeat the ignition purposely for various reasons.

Starting at the far right we have the neutral-gear detection system. It's a single ( usually green ) wire that comes out of the harness in its own weird spot, is thin because it carries very little current, and it must travel from the top rail of the frame out of the harness all the way to near the bottom of the bike at the gear box. The physical danger to that little wire are huge since it's not routed along anything sturdy so it has very little protection from being knocked around and its connection is in an area prone to gathering road muck over time. The other side of it goes to the JB. The neutral-gear detection system's sole job in life is to turn the bike off if the bike is in gear. In effect, it turns the gear shift into a kill switch.

Next to its left is the bikes way to defeat its own defeat system. Its a two way switch that is controlled by the IC. When the IC senses that the IC itself is functioning, it closes a switch to defeat the defeat system which allows the bike to run while it's out of gear ( or any of the other defeats to be explained below ). This switch also turns off the starter motor. So, given any reasonable engine that is ready to run, the starter motor is turned off automatically when it does run.

Next we have the clutch-cable detector ( Left Hand switch ) and the kick stand detector. Both of these systems can defeat the ignition as well, at least until the IC defeats the JB-defeat system on the whole. Now, you might want to keep those for safety reasons, and i'm the dead last person to advise anyone else about safety, but me? I trimmed those two items from the system on the whole because: a) I'm going to rewire the bike eventually and that's less wires to run b) less wires means less work in assembly c) less wires means a thinner more reliable and lighter weight harness d) fewer wires means fewer connections to keep clean and test during maintenance, and finally e) these two defeats are a pain in the ass.

Going left now in the diagram from that point brings us to the grounding and the battery hookups. The battery supplies the juice to the system and a bike can run with a full powered battery for at least 10 city miles ( i've gotten her to about 25 ). I mean to say, that it can run without any charging system at all, and on the battery alone without the stator or r/r charging it up again.

The diagram points out that the "main" ground on this bike is in several points. There is the battery ground, the chassis ground, the engine crankcase ground, the radiator ground, and also ground wires running to each and every running lamp. From a design engineers perspective, "what a freaking mess". Good thing this is not microwave or we'd need to add praying to the above technician notes. Every ground wire needs to be tested as described above in the test for wires. The connector on the crankcase may "look okay" but you may as well clean it now while the spray can is in your hand. Fortunately the lamps, though, test themselves for the most part. it lights, or it don't ( when hooking a battery to it ). And so, checking the main ground wires on each end is the thing to do.

That brings us, going left in the diagram, back to the ignition itself which was described above.

Hope this helps, and i stand corrected in advance.


P.S. I did not discuss testing for "shorts" above.

 

[Thorn]

Found this fairly confusing diagram showing the IC Ignitor box wiring. Maybe someone can figure it out.

I was trying to find how the IC Ign. is powered from the junction box. Looks like maybe the red/white wire, but the diagram has me befuddled right now. Think that red/white just branches off the start circuit, discussed in the Two-Wire Mod sticky thread.

Or you may have a dead IC Ign. box.

I believe the ignitor would be powered from the red wire coming from the killswitch (pin 3). This is the same voltage that powers the ignition coils. The black/white is a voltage OUTPUT to the junction box interlock circuit's anode. I imagine that when there's a path to ground on black/white (interlock in OK state) a relay coil in the ignitor allows spark to be generated from the main voltage from red.

 

[Thorn]

Whoops, sorry, you were talking red/white, not black/white.
red/white only gets voltage when the starter button is pressed, indicating to me that the ignitor circuit needs to do something special like "override the pickup coil timing" (who really knows) when starting.

 

[RoadHopper]

Whoops, sorry, you were talking red/white, not black/white.
red/white only gets voltage when the starter button is pressed, indicating to me that the ignitor circuit needs to do something special like "override the pickup coil timing" (who really knows) when starting.

Red White is the B+ line ( battery positive ). It goes through a fuse in the JB then out the other side. Then it goes to the kill-switch in series with the ignition key switch. So, in effect, as long as the key is on ( and that switch is clean and working ) and the kill switch is in the "Run" position ( and that switch is clean and working ), the ignitor's IC ( integrated circuit ) and the ignition coils' primary coils are both effectively the same as B+. Inside the IC then, is a transistor that turns itself to the "on" state ( similar to a relay ) which then connects the black wire at pin 4 on the ignitor to ground inside the IC. That in effect allows B+ to pass through the ignition coil primaries, causing an equal amount of power to be delivered to the ignition coil secondaries ( assuming the coils are in good shape ) except that the secondaries will be a much higher voltage and far less current. The secondary voltage then feeds up to the spark plug cable to the spark plug where since the voltage is high, the electricity can jump the spark plug gap on its way to ground ( crankcase is grounded ). And so, that also means that the spark plugs should be pulled and the threads examined to make sure they are not totally grimed enough to prevent spark, also the gap should be checked and the tips clean, followed eventually by the crankcase ground strap which finally leads the electricity back to the B- on the battery.

 

[Thorn]

Red White is the B+ line ( battery positive ).

Do you mean red (from kill switch)? not red white (from starter button)?

 

[RoadHopper]

Do you mean red (from kill switch)? not red white (from starter button)?

To be clear ( and yes it's easy to be hazy about such ),

I specifically mean the RED that is on the diagram. So, what i am saying is... if you look at that schematic, you can see the two switches in series from B+, then the R/W turns to Red making everything that touches that point ( that wire is a single "point" electronically speaking ) the same point as B+ ( battery positive ).

 

[RoadHopper]

Found this fairly confusing diagram showing the IC Ignitor box wiring. Maybe someone can figure it out.

What it does is show that the "current" version of the ignition coil mod, is only doing half the job and doing too much work to get there.

Here is a mod of that diagram... showing the "effective" situation after that mod... the wiring to the coils is redundant... for one thing, and unless one is certain that the existing wires are not working, then that part of the job is of no use.

The other thing is... the current mod is only doing half the job. What it does, is only on the back cylinder. It trades the circuit of the Integrated Circuit... the transistor normally is in series with the coils... and replaces that resistance ( which is tiny tiny ) with the ( tiny tiny ) resistance of an automotive relay primary. So, the current then is flowing higher ( i suspect without any ohm meter that sensitive to see ). But unless a second relay is installed to do the same trick on the front cylinder, the front cylinder's coil circuitry is the same.

 

[Thorn]

RoadHopper, what thread are you referencing as the 'current version of the ignition coil mod'? I'm curious to read the background that lead to what you've illustrated. Your schematic doesn't make sense to me... as in I don't see how it would work at all. Ignoring the mod design flaws you pointed out, I would have thought green would have to at least be relay-switched to positive voltage instead of to ground, but I'm just now trying to muddle through the coil circuitry, so my rudimentary understanding of the ignitor circuit could be backwards. The factory design looks like it is trying to push current from red to green, with green providing a path to ground somewhere in the ignitor circuitry, no?

 

[RoadHopper]

RoadHopper, what thread are you referencing as the 'current version of the ignition coil mod'? I'm curious to read the background that lead to what you've illustrated. Your schematic doesn't make sense to me... as in I don't see how it would work at all. Ignoring the mod design flaws you pointed out, I would have thought green would have to at least be relay-switched to positive voltage instead of to ground, but I'm just now trying to muddle through the coil circuitry, so my rudimentary understanding of the ignitor circuit could be backwards. The factory design looks like it is trying to push current from red to green, with green providing a path to ground somewhere in the ignitor circuitry, no?

I think i might have swapped the function of the green line from the ignitor side which needs to go to ground when a spark occurs ). I was recalling the mod from memory best i could. The thing that struck me the most though was that it only handles one cylinder.

Look at the diagram....

Trace from the B+ to the fuse,... okies.. like water current... electric current takes a path... from the fuse, goes through the two switches, so, let's presume they are both closed ( on ) and continue. That means the entire line is like a single wire, i.e. from B+ to BOTH of the coils is a solid "node".

So, when it's time to spark, it will only happen when that other side ( green wire on rear cylinder ) touches ground.

you could actually try this if you like... take out your battery, and a spark plug and one of the coils, hook them up with b+ to the same coil terminal it was connected to before ( careful, it can damage a coil to reverse polaritize ), hook a wire from B- to the outside of the spark plug. Hook the spark plug up to the coil using the spark plug cable. Hook the primary up to B+ now you only have one more available "tab" left on the coil... if you touch it to B-, you can watch the spark occur right there in your hand.

That last hookup is the green wire's job.