Ignition switch secret

The on going saga of no spark on 1200s Bandit '03 model has led me to investigate the ignition switch. 
Bandit Dave was a gentleman and produced an article regarding a resistor that Suzuki has hidden in the ignition switch. 
I have investigated mine only to find that it's all good. Unfortunately.
I took some pics along the way which may help someone else someday. 

Removal of the ignition switch is necessary.  





Drill out the two security screws to access the gubbins.





Pull out the rotating contact carrier.



Pull out the switch base.



On the back you will find the resistor that No one knows about. A security measure that the repair manuals do not cover. It measures 100 ohms and is in line in the power circuit to the ECU. 



A very sad Bandit and even sadder owner. 



The search continues.

Well, Mr Strawberry was clearly no help! I have a feeling that this will turn out to be something simple and will frustrate you to no end.  Have a beer and reflect.

PS: the kill switch is on isn't it?

Nope. The kill switch tests ok. On & the bike will crank. Off & no crank. 
I have tested everything, continuity wise. All switches are working as they should. 
I can only put it down to the ECU not functioning as it should, either because it's stuffed or not receiving the correct input signals. 
Very frustrating.

One of the things I like about old bikes (pre-ECU) is that there is a degree of simplicity about them that leads you to check the three basics (fuel, air, spark).  Diagnostics were much simpler, and if you knew how to tune carbs you were a genius. I just went through the 6-Sigma tune-up instructions for the carby kit I bought for the TRX and I'm super impressed with the instructions and how much tuning information is in them (wish I knew half this stuff).  The purchase price was worth it just to get the info.

I had a great example yesterday of simplicity at its best. Daughter's partner was getting a lesson on the tractor, driving on my old MF135.  I said "turn it off" and he did, but of course the engine kept running.  Strange look on his face, what's going on? I explained that it would run forever if you didn't cut the diesel flow to the engine with the manual fuel cut-off 'switch', as the electrics play no part in the running of the engine on a 1964 tractor.

Hope you find the gremlin before it drives you nuts.

I suspect the mark I ECU is different, if it would work for trouble shooting purposes you could try mine but I'm sure yours has more inputs.

Don't rule out side stand switch. My old mate Jimmy Bandit had an issue with his 96 Bandit and it was the side stand switch. Bridge it out and give it a try

G`day Bosco,
When I was in the same position as you, as I have already posted, one of the wires in that harness your showing, was broken, which was stopping my spark.
If I didn`t need my bike right now, I`d send you my CDI (Capacitor discharge ignition ), as its an 03.
When I was on the trouble shooting hunt, thinking I had CDI problems, I was going to send it to:

Small Coil Rewinds 
50 Edols St
North Geelong
Vic
3215
PH 0352788454

The lad that built my engine recommended this business, and after doing a bit more research, I think they`re about the only ones around that can PROPERLY, check if your CDI is buggered.

I hope you don`t have to go down that path, but if you do, give them a ring.


Or a bit of light reading for you:
[url=https://books.google.com.au/books?id=fAOpAwAAQBAJ&pg=PA59&lpg=PA59&dq=Motorcycle+CDI+ignition(Capacitor+discharge+ignition)+repairs?&source=bl&ots=cxEjJsytbd&sig=vsI5AdNCUmbRi6n4a1uYHYTJv44&hl=en&sa=X&ved=0CFUQ6AEwC2oVChMIg8Svr73ixwIVIVumCh1N1woh#v=onepage&q=Motorcycle CDI ignition(Capacitor discharge ignition) repairs%3f&f=false]https://books.google.com.au/books?id=fAOpAwAAQBAJ&pg=PA59&lpg=PA59&dq=Motorcycle+CDI+ignition(Capacitor+discharge+ignition)+repairs?&source=bl&ots=cxEjJsytbd&sig=vsI5AdNCUmbRi6n4a1uYHYTJv44&hl=en&sa=X&ved=0CFUQ6AEwC2oVChMIg8Svr73ixwIVIVumCh1N1woh#v=onepage&q=Motorcycle%20CDI%20ignition(Capacitor%20discharge%20ignition)%20repairs%3F&f=false[/url]

Thanks guys. 
I have metered the wires in the ignition switch and everything else. 
The ign switch tests up ok. 
The side stand switch tests ok. I have tried shorting it out of the circuit.  
There is a difference between our ecu inputs.  Thank you for the offer. 
A place that can test my ecu is exactly what I need. Thanks again fellas.

Howdy Bosco,

Question: was the bike previously running with the current ECU and ignition switch? If so, we are not looking for compatibility issues but a fault that has developed since the bike was running last.

The O/Y wire from the ignition switch to the ECU still has me troubled.
Here is a simple test to prove this circuit.

Disconnect the battery
Multimeter on OHMS range
Disconnect ECU plug
Put multimeter probe on O/Y orange/yellow wire or the pin on the plug if easier
Other meter probe to ground
Should read open circuit.
Turn on ignition key
Meter should read 100 ohms

Hey Dave. 
Bike hadn't missed a beat until two days before pink slip. All original parts. 
It really makes me believe in fate, karma etc. Although I can't remember doing anything to anyone that would bring this on. Lol.  
Have done the test that you outlined, with the correct result, almost. 
The resistor itself measures 98.6 ohms. Close enough in my book. when testing the loom and key switch I measured 90ohms. I can't see how the resistance can drop with the added wire, but that's what I measure.  
The resistor would provide a voltage drop in the line to the cdi. So instead of the full 12v, the cdi is expecting something less. 
As I'm measuring 12v at the coils, which are fed directly from the cdi, then I conclude that the cdi is powering up ok, just not cutting the voltage to the coils to provide the spark. 
Conclusion.  It's either the cdi or the pulse generator. The latter I have tested for continuity and output. The ouput signal may be less than is required,  but I can't tell without the peak voltage tool required.  
Ho hum.

Bosco15 wrote:Thanks guys. 
I have metered the wires in the ignition switch and everything else. 
The ign switch tests up ok. 
The side stand switch tests ok. I have tried shorting it out of the circuit.  
There is a difference between our ecu inputs.  Thank you for the offer. 
A place that can test my ecu is exactly what I need. Thanks again fellas.

Have you managed to eliminate the crank position sensor, it'll never fire if it doesn't know where.
It's a good suggestion to measure back at the ECU connector.

Thanks Pete. 
I have tested the pulse generator the best I can with only a multimeter.  
It has continuity and outputs around 6v a/c. Without the peak voltage tool required,  I can't be 100% sure that it's giving enough of a signal. 
Tracking down a cdi and pulse generator on ebay is my next step.

Unfortunately this info won't help with your problem but at least your resistance readings are pretty spot on.  It's very difficult to mass produce electronic components to exact values hence they have inbuilt tolerances.



It looks like your one has a colour banding of brown - black - brown - gold.  The last (gold) band is a 5% tolerance rating meaning it can be anywhere from from 95Ω to 105Ω - if anything it is actually pretty good as you're reading 1½% (discounting the accuracy of your meter).  Seeing the resistance changing (to 90Ω ) when putting other wires on is also normal, as other electronic components are now being measured and thus lowering the reading.  

Here's a colour chart, just note that most everyday resistors (of this style) have only four bands (they are missing the third band), just the first two, the multiplier (number of zeros) and the tolerance band:



Another reference on colour codes from Wiki.

It appears to me you need to get the CDI/ECU tested either yours on another bike or a known working one onto your bike, both difficult challenges.

Have you looked at and cleaned all the ECU and pulse generator connector pins ?

Something tells me we have a real simple issue here and maybe Barry's suggestion of cleaning the connectors on the ECU might be the solution. You should also check the connectors to make sure any of the pins have been bent or flattened. We really need to check the simple things before diving in to the "deep end".

OK let's start getting serious

You mentioned that you had measured around 6 volts AC on the pulse generator. Check if this same voltage is also present as close to the ECU plug as you can get

According to my information the ECU has another plug having 4 wires. It's multimeter time again.

The 4 wires are :

B/W       0 volts (ground) confirm on OHMS range

O/W       +12 volts

W    output to one coil

B/Y output to other coil

Putting your multimeter on either of the two [W or B/Y] and the other probe to ground check for a reading on either AC volts or DC volts ranges. I suspect there will be nothing as there is no spark from the coils. I wouldn't suggest holding the metal parts when doing these measurements. I don't consider it to be lethal but a jolt could result in you spilling your beer

I reckon the peak reading adaptor is a simple integrator circuit consisting of a resistor and a capacitor but as we don't have this knowledge let's move on.


But wait there's more. I'm not sure how keen you are to continue the fault-finding however if you have not run out of enthusiasm, check out these You Tube videos.


https://www.youtube.com/watch?v=juhri_NxQcQ


or


https://www.youtube.com/watch?v=TWsE2tPjHuo



This is certainly an option to consider. It will cost you less than $10 from Jaycar and maybe the salesman in the store might even put it together for you.

Howdy Bosco,

You mentioned earlier than you had a second ECU.

Has it got the same part number?

If so, and assuming it also doesn't produce a result should we assume you have two "dead" ECU's?

I reckon it's possible but a little unlikely which means there is still a fault within the bike

My money is on a damaged connector where a pin has lost tension and thus the ability to mate correctly.

I had a recent experience on a friend's BMW where a wire in a plug had a crimp pin where the copper wire had fractured but it was still  held together by the insulation.

Don't give in just yet

I'm no help on electrickery stuff as someone here calls it, but it's great that there are very knowledgeable people here to help with these issues. I'm sure all members appreciate it.

Boatz wrote:I'm no help on electrickery stuff as someone here calls it, but it's great that there are very knowledgeable people here to help with these issues. I'm sure all members appreciate it.

You said it Boatz. No one appreciates the help more than I. 

Dave. I have another CDI coming from Ebay. Will see if it solves my problem when it arrives. 
I really do appreciate your on going Input and encouragement. 
Time poor, I am only managing to get any real diagnostic time on the weekends. 
Great point about pins not connecting well. I have metered every wire from the cdi plug to their terminations, but have not checked that the females are tight and connecting well when plugged in. This i will do. 

Once again, knowing that my brotherhood and sisterhood of riders can be called upon for their vast knowledge is of great comfort. 
This is the best forum i have ever had the priveledge of being part of. 
Thanks guys and gals.

Ewok1958 wrote:One of the things I like about old bikes (pre-ECU) is that there is a degree of simplicity about them that leads you to check the three basics (fuel, air, spark).  Diagnostics were much simpler, and if you knew how to tune carbs you were a genius. I just went through the 6-Sigma tune-up instructions for the carby kit I bought for the TRX and I'm super impressed with the instructions and how much tuning information is in them (wish I knew half this stuff).  The purchase price was worth it just to get the info.

How does the old girl go now, Dave, after a carb tune?

Murphy's Laws

I cannot recall it exactly but one of Murphy's Laws states:

"Any item you have a spare part for will not be at fault"

Which eliminates ignition coils, leads and spark plugs.

In your case it also eliminates the ECU.

Howdy Bosco,

Things seem to have gone quiet on the bike "no go" project

BanditDave wrote:Howdy Bosco,

Things seem to have gone quiet on the bike "no go" project

 
Yes Dave, between a broken ankle, sick parents, flood, a trip to Japan and a house move for Chris, unfortunately the old girl has taken a back burner for a while. 
I went through every connector and wire in the bike with a multimeter. Got a second hand ecu. Still no spark. 
She will live again, one day.