Questions About Rectifier Testing

The stator checks out perfectly.

I tested the pulse generator, and it reads low. Acceptable range is 450-500Ω, and the white/yellow -> yellow and white/blue -> blue resistance tests show 302Ω and 306Ω, respectively. Would these low values keep the bike from sparking?

 

it may very well be. if the output of the pg is too low it may not trip the input on the cdi and therefore will not fire the coils

 

Man, I hope that's the problem. I'm running out of things to test!

 

Well the RR has nothing to do with starting, but the coils do--how did they measure? What about the cam pulse generator?

While not exactly within the 450-550 ohm range your pulse generator is not open circuited and not short circuited--when the magnets pass they will generate a pulse. You could hook up your meter and measure the voltage generated (an oscilloscope would show it better).

What about the igniter boxes?

Without definite defective items you will have to swap out and/or replace parts one at a time till you get it running...

 

I did a search about that, and I found a bunch of people say that it won't affect the spark, and a few that said it would. I didn't know either way, so I figured it was worth a shot.

The coils are all good. When I got the bike, it seemed like 3 out of the 4 plug wires were shot. Replaced everything with another set of coils and wires and everything checks out OK now.

The camshaft pulse generator hasn't been tested yet. Does the N-model have one? The Haynes Manual specifies G-models when referencing the camshaft pulse generator.

Another thing I want to check is the sidestand switch. The stop switch checked out OK, though.

Boxes? Do you mean the spark unit, or is there something else you're talking about? The PO said that he put in a new computer, I assume he's talking about the spark unit. AFAIK, there's no real way to test it. The manual says that if it's bad, you'll find out by process of elimination. It also says that you can bring it to a dealer to be tested, but I asked the guys there and they said they can't do it.

That's pretty much what I'm doing bc some of the tests (as you've seen) have been inconclusive. I can't seem to figure out which part specifically is causing the problem. On the plus side, I'm running out of things to replace! Knowing my luck, I'll have replaced everything and find out that it was a simple broken wire.

 

Sorry it is called the Ignition Control Module, ICM, and there is only one.

Go thru the troubleshooting in chapter 16 of the FS Manual is about all you can do...

 

Have you seen this? How to test.

YouTube

And

YouTube

And

YouTube

 

I had seen the first video, but not the second and third.

My new pulse generator came in today, and guess what. It's resistance is also reading in the low 300s, so it looks like the one on the bike isn't necessarily bad. I have a feeling this bike will never run. I'm running out of ideas.

Kill switch was good when I tested it last year, but I can test it again. If the sidestand switch was bad, the engine wouldn't even crank. Right? Same for the clutch switch, I assume. I mean, you wouldn't want the bike to lurch if you have the kickstand down, in gear, and hit the starter. Same for having the kickstand up, in gear, but without clutching in. If you hit the starter, the engine would crank, and the bike would lurch. Seems like common sense to me, but bikes are funny things.

Neutral switch maybe?

This thing is really making me scratch my head.


EDIT:

From the Haynes, regarding the neutral switch: "... this switch is part of the starter safety circuit which prevents the starter motor operating whilst the transmission is in gear..."

Regarding the sidestand switch: "... this switch is part of the starter safety circuit which prevents the starter motor operating whilst the transmission is in gear..."

Regarding the clutch switch diode: "... this switch is part of the starter safety circuit which prevents the starter motor operating whilst the transmission is in gear..."

Regarding the clutch switch: "... this switch is part of the starter safety circuit which prevents the starter motor operating whilst the transmission is in gear..."



They're all also ignition cut-outs, but it seems like if any of these switches were bad then the engine wouldn't turn over at all. And, yes, the bike IS in neutral when I try to start it!

 

Yes the motor cannot start in gear with kick stand down, the gear must be in neutral and kill switch on running. the sidestand only kill the engine when in gear. But yes with clutching drawn engine should start.
If possible disconnect switches one at a time, maybe a shortcut?

Have asked others in this country, more people have had the same problem, several have had good luck with new spark plugs

The videos are all about testing of key electrical components.

 

do you have no spark on all 4, or no spark on either the front or rear pair?

do you measure battery voltage between the black/white wire and the green wire at the ICM when the key is on and the kill switch is in the run position?

 

Spark plugs are all brand new and gapped.

No spark on any cylinders. I haven't measured that voltage yet. It's dark, but I'll see if I can dig anything up. Am I disconnecting the ICM and testing the harness, or leaving it hooked up and testing the "backside" of the plug? Or does it not matter?

EDIT: Just looked at the wiring diagram. Looks like it makes more sense to leave everything hooked up. The Green voltage goes INTO the ICM, and the Black/White goes OUT of the ICM to the coils, correct?

 

Measure at the ICM on the back side with everything connected. The black/white is the hot wire from fuse number 4 thru the kill switch to the ICM supplying battery voltage (+12) and green is the ground (-).

The Black/white wire does run to each coil and provides the current flow into the coils during the dwell period, and it should be verified (+12 to ground) at each coil also, but the one into the ICM provides power to the ICM to function.

 

I'll need to find a small prong or something to stick in there, I can't seem to get a good connection with the meter leads. Or I'll strip a small patch from the wire itself and test from there.

That's work for tomorrow, though. Thanks for the info, I'll let you know what the results are.

 

Well the results are in:

Positive Lead -> Black/White ------------- Kill switch On = 152.7 mV (Yes, mV) Off = Negligible voltage
Negative Lead -> Green

152mV is pretty negligible in itself, but it's steady. When I flip the kill switch off, the voltage drops off even more. Turn it back on, and the meter goes back to reading 152mV.

Pos Lead -> Black/White
Neg Lead -> Battery (-) Terminal ------------- On = 12.74V Off = Negligible

Pos Lead -> Green
Neg Lead -> Battery (-) Terminal ------------- On = 12.39V Off = Negligible.


The second and third tests were just "I wonder what happens when..." kind of tests, since I don't seem to be getting battery voltage between the Black/White and Green wires like you said I should.

The setup (correct me if it's wrong):



The ICM has three "green" wires coming out of it. Green/White, which goes to the sidestand switch and is also tapped into by the clutch switch; Green, which also goes to the sidestand switch, and is tapped into by various components; And Light Green, which goes to the neutral switch and the neutral switch diode.

I am testing the regular Green wire, correct? If so, what do you think this means? Fried ICM?

 

The second test has the correct voltage on the black/white measured to ground, which should have been the result of the first test--so this is indicating that there may not be continuity between the green wire (yes you got the correct green wire) out of the ICM and the chassis ground/battery negative. It also is an indication that the ignition switch, kill switch, main fuse and fuse #4 were working okay for your test.

The results of the third test are totally unexpected--seems like there may be a short-circuit in the ICM and/or the green wire is open-circuited from ground.

i would recommend that you disconnect the battery ground cable and the ICM connector and then check for continuity/resistance between the green wire and the chassis ground lug. It should be nearly zero ohms. (e.g. 0.1-0.2). If it does measure okay, then it would seem that the ICM is bad. If there is an open circuit, i.e. no continuity, then you will need to trace the green wire from the ICM connector to find where it has been cut. good luck you are almost done.

 

Ok, this is what I've got:

I disconnected the (-) terminal and attached the lead to that wire and the green wire. With the kill switch off, I get "0.L", no reading. Kill switch on, I get 5.73MΩ. Yup, capital 'M'. It reads the same whether I ground to the negative wire off the battery or the engine block.

When I first hook everything up, sometimes the meter reads 182.2kΩ, but turn the kill switch off then on again and it goes back to 5.73MΩ.

Also, it doesn't matter what position the key is in. On or off, the readings are all the same.

ICM Test - YouTube

 

Congratulations you have found the reason that your bike won't start--the green wire at the ICM is not connected to chassis ground. Now all you have to do is trace the green wire in the harness to find where it has been cut or is not connected to the chassis ground lug, and remedy that condition.

 

That would've been great news if I did the test correctly! I never disconnected the ICM.

I just went outside, disconnected it, and did the test again. Key on or off, Kill switch on or off, the reading is a steady "0.L"

So yeah, all the prior results were with the ICM plugged in. Whoops... But does that pretty much zero in on a faulty ICM?

 

It is a wire problem--the green wire is supposed to be connected to chassis ground which is also connected to the battery negative terminal. Yours is an open-circuit, there is no connection. Either the green wire is broken, cut or not attached to the ground lug. Look for a ring-terminal lug with green wires bolted to the frame somewhere near the RR.

 

This guy?:



I was hoping it simply had come loose there, but no such luck. I'm about to leave town for work, so the digging will have to wait until I get back tomorrow. I guess what I'll do is test between all visible points of that wire to try to narrow down the break. I don't suppose I could just splice a line between the green wire, up by the ICM, and that lug? Take the easy way out?