Theory on CDI and No Ohms at Crank Coil


Information and questions on GL1200 Goldwings (1984-1987)
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Big Dogcrux
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Theory on CDI and No Ohms at Crank Coil

Post by Big Dogcrux » Wed Oct 11, 2017 7:13 pm



:ugeek: I am no expert on Goldwing electrical circuits, but I was trained by the sub navy to troubleshoot circuits. And this is important to me because the GL1200 Limited is currently my father's scooter and I want to buy it for a 1000 dollars if we can get it to run. Now I have read about connectors being old and bad wiring. Normal stuff in today's modern world of electrical circuits.
My dad's bike was working just fine! Then he changed the oil one day and he found no spark. I trust my dad with a multi meter. He worked as a mechanic for several years and was on the team at K and P cycles in Orlando when Jeff Farmer beat the establishment as a privateer on a K and P Yamaha.
So we argue about modern components alot! The differences between solid state amps, diodes and other switches confuses guys that grew up in the 60's and 70's.
So the Goldwing has no spark. Period. He traces the wiring diagram down to the ECU under the seat and found zero ohms at room temperature on the pins to the crankshaft coil....
I understand the electrical switch. But the bike is getting old! Dirty as hell. And to take the timing cover off and polish the connectors sounds like preventative service to me. But then he wants to insist that its a coil! A coil? Like the symmetrical coils on Novas and Vegas? Circular? Coils that use wire rolled around a plastic tube? Or a crankshaft coil that registers amps and voltage like a block of platinum that stores logic in binaries perfectly?
So this is where I am with my dad. We use troubleshooting techniques just like every body else! A short at the pins, excuse me...an open at the pins is where we are! An open at the crankshaft coil connector pins down under the seat at the ECU.
That's the logic. The binary. But if the circuit does not flow from one side to the other because of oxidation or corrosion or a bad wire or a bad connection that would also cause zero ohms at the pins when there are ohms in other places.
So I have read about this problem. And I am starting to understand why the primary ignition and the pulse generator should be a good system that functions like a distributor for a Goldwing. It should work good! The pulse generator is on perfect time from the mechanical dynamics of the engine. A pulse is the binary. The pulse goes through the primary circuit to the coil where energy is stored in a capacitor and when the pulse is the emitter at the capacitor or coil then secondary energy flows to the spark plug intermittently and proper. Of course...right? Theoritically perfect! But then a short? At the pin? No spark at all? I would go straight to the source of the pulse generator and clean those connectors just like the genius advisors on the forum. Free and perfect information! Polish the connectors at the pulse generator? Logic starts there...right? Logically. No spark? Go to the source first anyway. Preventative service at the pulse generators and its connectors would be very anal of any of my old racing buddies...sounds good! Thanks for the information. But what if the pulse generator isn't the problem? Primary current goes to the coil? So is it an ignition coil or a crankshaft coil? And if there is a crankshaft coil...does it it feed into the primary circuit to the ignition switch? Or somewhere on the secondary side to the spark plug?
Is my father intentionally trying to confuse me?
But we do have an open at the pins...on the ECU connector under the seat.
When you see the dirty, old bottom of the seat and top of the motor of an old GL1200 '85 you laugh...if you like a clean toilet and ears...you know? Bound to be something! Down the wire somewhere....
And I really dont know a thing about the Goldwing GL1200; but I am a veteran ET3...so I can relate to the CDI a little.
You guys that come from Canada and Utah that build jets and missiles might be able to analyse semi conductors and the possibilities of opens at the sensor a little better than my crazy mind. Go for the theories with me...the scientific process is always good with me.
And if it is an open? Why? Why would a modern solid state device open at the primary ignition circuit? Why would a coil on a Goldwing? Is the coil a wire, a capacitor like platimunum, and why the hell cant you buy one?
An interesting machine!
Thanks for any good help guys and gods!


:ugeek: Steve Sheppard

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virgilmobile
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Re: Theory on CDI and No Ohms at Crank Coil

Post by virgilmobile » Thu Oct 12, 2017 8:42 am

Those coils you refer to...There simply a winding of fine wire around a metal core and magnetized.When the magnetic field is disturbed by the trigger wheel the magnetic field collapses and a small voltage is developed on the coil wires.The ignition module sees this voltage as a trigger pulse to fire the circuit to operate that coil.The pulse coils are also used to reference crank position.
Yes there difficult to fine..Some say,with a bit of modification on the mount,that a pulse coil from a gl1500 can be fitted.

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Re: Theory on CDI and No Ohms at Crank Coil

Post by virgilmobile » Thu Oct 12, 2017 9:34 am

A bit more info...Because this circuit is operating on a very low voltage/signal pulse any poor connection will kill it.
I have heard also that the windings in the pulse coil can fracture/crack and become intermittent.Usually showing up when they get heated up.The pulse coils are not directly wired to the module..they do get connected with a plug on the main harness.A good place to isolate what part of the circuit has the problem

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Re: Theory on CDI and No Ohms at Crank Coil

Post by Big Dogcrux » Thu Oct 12, 2017 1:29 pm

:geek: Well...thank you Virgilmobile for your input. Dad says...insists that is exactly what he said already. I talked about the CDI with him this morning. To me...a perfect system for generating spark at the plugs with very few mistakes. I suppose this is why theze sleds last for 32 years! I hardly believe these machines have such little era in such humidity in the south. The pulse plate is where we are heading; to examine the dynamics from there. Dad seems to be there with you on that! He is good! So he found the wire open at the ECU under the seat and at the connector for crank angle sensor. That is the open or zero ohms reading he found. My question this morning opposed as everything is working but neither coils fire 1,3,2 or 4. If the conduction at the pulse generator is a tiny voltage, then a module or solid state amp isnt used? And if it is used, without any emitter at the base or collector of the amp wouldnt that cause the amp to go into a default logic somewhere? Like a reset switch? And dad says it is wired directly from the pulse generator to the ECU. Blew my reset theory about logic in a circuit. Thank you.
:ugeek: Steve Sheppard

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virgilmobile
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Re: Theory on CDI and No Ohms at Crank Coil

Post by virgilmobile » Thu Oct 12, 2017 2:18 pm

The insides of the ignition module is a secret by Honda.
It's all about the same in operation.A small pulse triggers a large power capable switch(usually a FET) by magic electronic components.All these parts just replace points and condensers.
Honda added more needed control imformation by adding the crank angle sensor.Needed for electronic fuel injection and it's control module.
My 88 Gl1500 uses 2 pulse coils to fire 3 coils.
One sends pulses for the spark and the other for crank position.The rest is done by a mapped program in the module.

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Re: Theory on CDI and No Ohms at Crank Coil

Post by Big Dogcrux » Thu Oct 12, 2017 3:10 pm

:geek: Thanks! I read about the crank angle sensor on the '85 GL1200 being part of the open circuit. Dad and I are going to dig it out eventually. We got the idea now. So to find the company that can rebuild it is a question and how much?
Or to order one from an 1500 and modify the mount is the idea we are seeking.
But still...thanks!
The magic...the mapping...really uses special and perfect flowcharts to the specific languages of the designers and engineers.
The fuel injectors are more efficient with exhaust products and take up lesd space; so technology found the logic and mapping that is stable enough to perform multitasking and switching signals.
The circuits of diodes and amplifiers are magic! They are more efficient mostly. I'm proud of Honda and companies like BMW that started all this change in timing solutions. Really smart stuff!
But there is still a language that can be understood by elementary engineering knowledge and language.
To know the calibration and design; and of course the exact mapping from any computer logic frustrates me.
I would love to reach the level where computers can map the current better and diagnose more perfectly! But of course that wouldn't sell motorcycles would it? Good mechanics or okay mechanics could simply Turn a diagnostic switch; charge the secondary mapping parallel to the primary and the parallel circuit could find the opens and broken connections to serve the output computer, "replace crank angle sensor" with part #***** or call #****** for service advise. Bikes and cars would last longer. People could easily manage turn key diagnostics and we all could do simple steps to fixing very complex problems.
In a better confederacy that might be possible someday....
:ugeek: Steve Sheppard

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Re: Theory on CDI and No Ohms at Crank Coil

Post by virgilmobile » Thu Oct 12, 2017 4:04 pm

When all is said it's still boils down to common sense.Just because a computer says there is a failure in a area doesn't mean that part is bad.Computers report trouble codes generated by "out of spec" conditions..it's still up to the tech to determine the root cause.
Case in point..My Mercury mountaineer I purchased to restore had multiple error codes.Mostly saying I had a few sensor problems.
The sensors we're not at fault at all.Testing each one in the error list proved them ok...
The final problem was a defective alternator..
It still worked but also had an enormous amount of random voltage spikes on the line.
I could see them with an oscilloscope.
The computer also "saw" them and added them to all the sensor inputs...It went nuts..even the theift alarm went off.
New alternator...no noise..all errors stopped.

Always test and confirm before buying stuff in hopes it will fix your problem.
Keep us posted too..take pictures..ask questions...post your results.. thanks

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Re: Theory on CDI and No Ohms at Crank Coil

Post by Big Dogcrux » Thu Oct 12, 2017 5:29 pm

:ugeek: Wow! You really hit the nerve. Using an oscillascope? You are really using the ole noogen there. I enjoyed using oscillascopes verses handheld multi meter any day!
The navy was doing such good work with me in the early 90's (Gulf War veteran). Everything you said was so true! I have never heard an altenator story quite like that one! My dad and I ran a mobile shop called "Engine Tech" in the late 80's and 90's. Dad was going to electronics school in Washington DC when I came along and then started making better money turning wrenches. He did good with shops all through the 70's and 80's making some good money rebuilding carbs especially. So he got some money from his mom and started his own show- Engine Tech...and we serviced the entire Orlando area until about 1996 when all these computer codes (like you are saying) started costing him money because it was a crankshaft sensor! On a Lincoln Towncar especially. So I ran the company for awhile...as far as I could get it. We had many commercial accounts, PM services and minor repairs mostly. And of course our clients all over the place. We were racing dirtbikes...harescrambles and enduros with K and P cycles keeping pace with our machines. K and P eventually built a Yamaha and won Daytona my freshman year in college! As privateers! I was proud of my friends and my people in Orlando.
So we kept Husquavarnas and a RMX for awhile.
Dad kept a small handheld computer for the diagnostic ports, but just like you said. Even with the 2 of us...and every code and theory there was no exact science to vacuum, sensors, plug wires or bad fuel injectors (which we saw a few times).
The industry changed fast and destroyed Engine Tech's ability to make a profit.
Dad was a carburator genius! We must have rebuilt two carburetors a week in the early 90's. At about 350.00 a piece. Something like that...lucrative.
We had a Suzuki ES550e in the back of the service truck and I would run parts as fast as I could. We did some good work, finishing most of our "jobs" in the afternoon.
So we have been down this eccentric road before; I suppose that one reason he bought an '85 Goldwing in the first place!
If it was truly my bike at this point; I would go through the five major components I found and of course carefully service the entire electrical system the best I could with dialectric compound.
The pulse generator and coil, the crankshaft angle sensor, the cam angle sensor, the ignition coil unit, the cruise valve fuse, the other ignition components. Of course that would take me some time, a notebook, parts and complacency, but I believe this machine might still be worth a few rides if the swing arm bearings dont ruin my rebound in the back too much....thanks again.
:ugeek: Steve Sheppard

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Re: Theory on CDI and No Ohms at Crank Coil

Post by Rednaxs60 » Fri Oct 13, 2017 12:58 am

Been following your thread with interest. virgilmobile is a good resource to have. I had to replace the Ns (crankshaft) sensor in August. In browsing the forums I found one post where the fellow replaced his Ns sensor with a PG harness from an '85 Aspy. He installed both sensors but only hooked up one. He had the second sensor as a backup - wouldn't have to take the front apart later. I did the same to mine, installed '85 ASPY PG sensors - they fit in the same upper and lower position. I took one set of wires and disconnected the wires from the one connector and installed in the one for the '85 LTD. Works very well.

Using a 1500 and adapting it is a bit of a chore. My LTD was modified by the previous owner to use a 1500 sensor. He had to modify the upper mount arrangement to get the sensor to fit properly. He had to remove some of the metal from the engine case where the securing bolts fit.

If you can source an '85 ASPY PG sensor harness - less expensive than the 1500 sensor I believe, this would be my preference instead of using the 1500 sensor and modifying to suit.

Just a thought on your Ns issue.

If the Gr/Gl (camshaft) sensors are bad, have a potential solution for that as well - found it on the CX500-CX650 Turbo forum.

Cheers
"When you write the story of your life, don't let anyone else hold the pen"

Ernest

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Re: Theory on CDI and No Ohms at Crank Coil

Post by Big Dogcrux » Fri Oct 13, 2017 8:12 am

:geek: Hey thank you RedHaxs! This thread has been very interesting so far. Thanks to both Virgilmobile and Redhaxs. Interesting to get into having an open mind about the dynamics at these sensors!
Makes me wonder about all those genius techs out there that spend too many hours working on these Goldwings and losing money...charging loyal customers for just a few of those hours...lol. As a tech...I did sometimes!
Companies like Honda could easily train a couple techs to be more user friendly....
I like Goldwing Docs! Great info if you keep notes!
I might just buy the Goldwing from Dad if we can get the monster running.
Have a great day guys.
:ugeek: Steve Sheppard

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Re: Theory on CDI and No Ohms at Crank Coil

Post by Big Dogcrux » Fri Oct 13, 2017 7:15 pm

:shock: If you guys get time to read this thread some more; today my dad pulled the crank angle sensor off with the greatest of ease! And measured the ohms at the bottom of the wire harness to the wire and found nothing, not a **** of resistance! No impedance...nothing to keep ergs of electrons bundled or accumulations of radiation. Gentlemen..I think he has nailed it, but then you know about these machines being tricksters! I hope he has it by the balls now. Now we begin the quest for the replacement part...the 1500 modification and from whom. The company that rebuilds these NS parts or the PG sensor trick?
So Mario brothers moves on to the next level....
Thanks again for the help guys.
:ugeek: Steve Sheppard

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Re: Theory on CDI and No Ohms at Crank Coil

Post by virgilmobile » Fri Oct 13, 2017 9:39 pm

Ya got it.Sounds like a broken wire keeping the magic smoke from getting out.
Take pictures along the way and document your success.

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Re: Theory on CDI and No Ohms at Crank Coil

Post by Rednaxs60 » Mon Oct 16, 2017 12:00 am

I'd go with a PG sensor from an '85 ASPY and install it. Less hassle, no adjustment when installed and no modification of the mounting arrangement. Just need to use the right wires from one of the sensors.

Good luck.


"When you write the story of your life, don't let anyone else hold the pen"

Ernest

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