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An Electrical puzzler


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Here's one for all you electrical geniuses - if you can solve this problem I'll name my next male child after you.:Laugh:

 

Here's the back story - last year, we were just about home from a long trip & the bike dies on the freeway. Long story short - It turns out that 2 of the leads had detached from the bottom of the ignition switch. The local Hoinda dealer fixed the bike and when I pick up the bike from the dealer, it runs fine. But here's the glitch - with the bike in nuetral & on the sidestand, it will not start or run unless the clutch is in. Pull in the clutch - it starts right up. If I sit on it & put the sidestand up (& bike is in nuetral), I can let the clutch out and it will continue to run.

 

I have replaced the ignition switch & the sidestand switch, and the clutch switch and inspected the nuetral switch (it is a mechanical switch which seems to be working fine). Nothing changed. I have inspected all the fuses I know of and all the electrical connections. Is there a relay or fuse someplace I am unware of? :confused24: Broken connection in some hidden spot? :think:

 

I would appreciate any useful information on resolving this.

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Well, this really shouldn't be all that hard to solve. You don't specifically say, but is this problem with your RSV? I only question that since you mention a Honda dealer.

 

Next question - does your neutral light work correctly? Again, that seems like an obvious thing you would have already checked, but you didn't mention it. You said you "inspected" the neutral switch, but what does that mean? Did you use a meter and verify when it makes contact and when it does not? How about the resistance through the switch when it is closed?

The problem is absolutely in the neutral circuit, since what you have described is perfectly normal operation if the bike is in gear. But since you have verified the problem happens when the bike is in neutral, that pinpoints the circuit. The problem cannot be in the sidestand or clutch switch, since you described normal operation for both.

UPDATE after more thought: The above statement is probably NOT correct! The RSV should NEVER run with the sidestand down if it is in gear or THINKS it is because of a bad neutral switch. Just going from memory, but I believe the sidestand switch while in gear is a hard cutoff, so getting a ground through the clutch switch should not allow it to start or run in that condition. So the problem is a little more insideous than I first suspected. I'll Keep thinking on it.

 

The last unknown is whatever the Honda shop did to the wires - it is possible that they hooked something up wrong, causing the problem, but that is only speculation. I'll try to look at the schematic and see if I can imagine a way to make it act as you describe if the neutral switch is working correctly. :080402gudl_prv:

Goose

Edited by V7Goose
Correction
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I'm not sure if you'll find this usesfull but anyway ...

 

I'm not sure about Handling the Signals for these safety related Switches on a 2Gen.

 

On a 1Gen or a Vmax, there's a Starter Circuit Cut-off Relay, which is operated by those Switches. Maybe this is different on the 2Gen, because they handle many Things inside the CDI(Igniter Box). If such a Bike would behave like this, i'd go and check there and the related Diode in Diode Block.

 

You should check with the Wiring Diagramm to find out about this.

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You don't specifically say, but is this problem with your RSV? I only question that since you mention a Honda dealer.

Yes - 2000 RSV. Where I happened to come to a stop outside Beaver Dam there was a Honda dealer across the road. He came over to see if he could help, came back with a trailer, we loaded it up and he took it to the shop where it could be secured overnight.

 

Next question - does your neutral light work correctly?

Yes, it lights up just fine. Which is why I assumed the neutral circuit was OK. I did not check it with a meter - I had a helluva time finding it and could barely see the damn thing once I did, let alone get the meter probes in there. Plus, I am not really good at diagnosing electrical switches. And the manual was not a great deal of help here either.

 

 

You said you "inspected" the neutral switch, but what does that mean?

I visually checked it as I shifted in and out of gear and could see the switch go from ground to contact.

 

Did you use a meter and verify when it makes contact and when it does not? How about the resistance through the switch when it is closed?

 

NO, I didn't - but the the neutral light lit up when it was in neutral and went off when it was put in gear.

 

Yeah, the unknown shop work is a big question mark. Prior to it's untimely stop, the bike worked fine. That said, everything else electrically works fine - signals, lights, horn, radio, clock, cruise - no other problems that I have become aware of.

 

I appreciate your help on this. Like I said, trying to run down an electrical problem is not my strong suit. Tell me what to check and what the results should be, I can do that. Standing by..........

 

Squeeze - where would I find the CDI box? And can 1 diode be replaced (or by-passed)? Or this another expensive component that needs to replaced? :doh:

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I added a comment to my first response, so I won't repeat it all here other than to say my initial assumptions were wrong - I jumped to a conclusion without thinking it completely through. More later, IF I can come up with something useful!

Goose

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..........

 

Squeeze - where would I find the CDI box? And can 1 diode be replaced (or by-passed)? Or this another expensive component that needs to replaced? :doh:

 

I believe the CDI is beneath the Battery Box on your Bike, but this shouldn't you concern at the Moment.

 

You could download the Shop Manual from the 2Gen Tech Section and wade through the last Section - Electric - and look if you can find a Starter Cut-Off Relay somewhere in the Item List on the Wiring Diagram or even in the Circuit Descriptions on the Pages before. If there's one, your Bike Bike will most likely also have a Diode somewhere.

 

Goose will be back on this Issue, i'm sure about that.

 

I'll could have a glance tonight when i'm home, i have no 2Gen Shop Manual here in the Office Computer.

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OK, I still haven't gotten to the schematic yet to examine the circuit again in detail, but I DID go out and verify normal operation of the side stand/neutral/clutch interlock switches.

 

  • If the neutral light is not on, the bike will not run with the side stand down, period. The clutch makes no difference. This means that if it is running and you put the side stand down while it is in gear, it will stop. Neither can it be started under those conditions. If you hit the start button with the side stand down and in gear, you will see the normal engine temp and oil level lights come on, but you will hear no sounds.
  • If you are in gear with the side stand up and attempt to start the bike with the clutch OUT, it behaves the same way - the normal two dash lights come on while the start button is depressed, but no other sounds.
  • In gear, side stand up, and clutch IN, the bike starts normally.

One other piece of information - if the kill switch is on and you hit the start button, ONLY the engine temp light will come on, not the oil level light. That may help us determine if they made some abnormal modification to the wiring.

 

So please check and report back these things:

 

  1. Hit the kill switch and then press the start button. What happens (dash lights on or noises, such as clicking)? Any difference with side stand up or down?
  2. Turn kill switch back off (run position), place bike on side stand, in neutral, clutch out, hit start button. What happens?
  3. Bike still on side stand, clutch out, but IN gear, hit start button. What happens?
  4. Finally, bike still on side stand, IN gear, and clutch IN, hit start button. What happens?

For the above tests, I am particularly interested in what dash lights come on when the start button is pressed, along with any clicking you may hear (other than the normal fuel pump clicking the first time you turn the key on).

 

Now, with bike on side stand, in neutral and clutch in, start the engine, then let out clutch while still on side stand. Based on your first post, the engine should die. Does it? (I'm just trying to make sure I understand the problem correctly with this last test.)

Goose

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OK, I still need the answers to the questions above to maybe pinpoint your problem, but here is some information about how the circuits work, based on the schematic. The Yamahaha schematic is a terrible schematic, and there is little explanation about how almost anything works, so I can't swear I have interpreted it correctly, but here goes:

 

Near as I can tell, the way the side stand switch provides a hard cutout for the ignition is through a ground on the Ignitor Side Stand pin (SS) when the side stand is UP. The neutral circuit also provides a ground to the same wires through a diode in the Starter Cutoff Relay (SCR) when the bike is not in gear. So the bike runs when there is a ground applied to SS, and it dies if that ground is removed.

 

In addition to the ground supplied to the Ignitor, the side stand switch circuit ALSO supplies a ground to activate the SCR in conjunction with the clutch switch. Basically, your starter cannot engage unless either the bike is in neutral or the side stand is UP and the clutch is pulled in. Although this sounds similar to the ground circuit I described above for the Ignitor, it uses mostly different wires and connections on the SCR.

 

Somehow these two circuits are interacting, either through a miswired ignition switch, or possibly a shorted diode in the SCR. The ground to the SS pin on the Ignitor comes through the blue/black and blue/yellow wires in the three-wire plug to the ignition switch, so this would seem to be a likely place to look for problems after you had wires come loose there. Unfortunately, since the bike runs fine with the side stand up, that suggests the ground circuit from the side stand switch through the ignition switch to the Ignitor is working fine. Testing those circuits on the ignition switch can be a little tricky if you don't fully understand ohm meters and schematics since you can quicly ruin an ohm meter if you connect it to a hot wire, so let's assume that circuit is OK for now and concentrate on the neutral circuit that SHOULD be providing a ground to the Ignitor when the side stand is down.

 

From here on, I am just thinking out loud - maybe typing out the thoughts will lead me to a possible cause . . .

 

The first problem is that your bike does not run with the side stand down and in neutral unless the clutch is pulled in. The neutral should always supply a ground to the Ignitor through the diode in the SCR between the light green and blue/yellow wires, and the clutch switch is in a completely different circuit so it should have no effect at all (other than to allow the bike to be started). We know the ground from the neutral switch on the light green wire must be good since your neutral light works off the same wire, so it is possible the diode between the Lg and L/Y pins in the SCR could be open.

 

HOWEVER, if that is the problem, then we have to figure out how pulling in the clutch could possibly be providing a ground to the Ignitor to allow the bike to run with the side stand down. The isolation diode inside the SCR between the blue/black and light green wires would probably allow this.

 

Ding Ding Ding - we may have a winner! Assuming I have correctly understood your symptoms, it seems likely that you have a open diode between the light green and blue/yellow wires on in your Starter Cutoff Relay. To test that you will need to disconnect the relay and measure the resistance between those two pins with an ohm meter set on the x10 scale (or use the special diode check scale built into most modern digital meters). With the negative lead connected to the Lg pin on the relay and the positive lead to the L/Y pin, you should have some measurable resistance (the exact amount is unimportant). If you reverse the leads, you should read infinite resistance (same as when the leads are not connected at all. If you read an open (infinite resistance) both ways, then the diode is burned up, as if it is not there at all. This could have happened if one of the wires that came loose shorted out.

 

If you DO find a bad diode here, then you should also track down and check another diode in the side stand switch circuit. On the schematic it is number 12 and only labeled as "Diode", connected with a two-pin plug to the side stand switch circuit using blue/white and blue/yellow wires (blue/white from the switch, blue/yellow to the SCR). I have no idea where it is, but if something fried the diode in the Starter Cutoff Relay, it could have possible shorted out this diode also. Right now I think you may have been lucky you didn't fry the Ignitor, so best to check everything to keep that luck!

 

Goose

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Question: what caused the wires to be pulled from their perfered location on the ignition switch, and is something now shorting out there?

 

Did the dealer put the wires back to where they should be, or did they get reversed?

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Guest tx2sturgis

Ok I realize Im not quite in the loop on all this...but I have a sincere question:

 

Is it possible to bypass all that safety stuff? How would you do it? Would it be simple or difficult? Reason I ask is that in all my years riding dozens of bikes, I never killed myself either starting in gear with the clutch out, or trying to ride off with the sidestand down. Do we REALLY NEED all this stuff on the bike? I mean, were not beginners.

 

Only once or twice in 40 years of riding have I left a sidestand down when riding off, and it nearly got me. This was on a Suzuki GS 750. My Harley and most Harleys dont have any of this stuff and somehow we get along fine on them. They DO have a sidestand thats designed to foldup if you ride off with it down.

 

Mine is working perfectly now, but say in 5 or 10 years, I want to bypass some or all of this, has anyone ever tried?

 

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I did this on my 89. I have a hidden Switch, that Bypass's EVERYTHING, on page

7-11, block diagram. Its a double pole, Single throw switch.

 

If anything fails, except, the start solnoid. I can throw the switch, and bike will start and run. I just don't trust all that Stuff,

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OK, I still haven't gotten to the schematic yet to examine the circuit again in detail, but I DID go out and verify normal operation of the side stand/neutral/clutch interlock switches.

 

  • If the neutral light is not on, the bike will not run with the side stand down, period. The clutch makes no difference. This means that if it is running and you put the side stand down while it is in gear, it will stop.
  • CORRECT
  • Neither can it be started under those conditions. If you hit the start button with the side stand down and in gear, you will see the normal engine temp and oil level lights come on, but you will hear no sounds.
  • CORRECT
  • If you are in gear with the side stand up and attempt to start the bike with the clutch OUT, it behaves the same way - the normal two dash lights come on while the start button is depressed, but no other sounds.
  • CORRECT
  • In gear, side stand up, and clutch IN, the bike starts normally.
  • CORRECT

One other piece of information - if the kill switch is on and you hit the start button, ONLY the engine temp light will come on, not the oil level light.

CORRECT

 

That may help us determine if they made some abnormal modification to the wiring.

 

 

So please check and report back these things:

 

  1. Hit the kill switch and then press the start button. What happens (dash lights on or noises, such as clicking)?TEMP & NEUTRAL LIGHT ON, NO CLICKING.
  2. Any difference with side stand up or down? NONE
  3. Turn kill switch back off (run position), place bike on side stand, in neutral, clutch out, hit start button. What happens? CRANKS, BUT WON'T START
  4. Bike still on side stand, clutch out, but IN gear, hit start button. What happens?TEMP & OIL LEVEL LIGHTS (RED) COME ON, DOES NOT TURN OVER
  5. Finally, bike still on side stand, IN gear, and clutch IN, hit start button. What happens? SHE FIRES RIGHT UP

For the above tests, I am particularly interested in what dash lights come on when the start button is pressed, along with any clicking you may hear (other than the normal fuel pump clicking the first time you turn the key on).

 

Now, with bike on side stand, in neutral and clutch in, start the engine, then let out clutch while still on side stand. Based on your first post, the engine should die. Does it?YES

(I'm just trying to make sure I understand the problem correctly with this last test.)

Goose

 

Thanks for all the mental gymnastics, Goose.

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Question: what caused the wires to be pulled from their perfered location on the ignition switch, and is something now shorting out there?

 

Did the dealer put the wires back to where they should be, or did they get reversed?

 

I don't know what caused them to come off - just a weak solder connection. Vibration, most probably. No, nothing is shorting at this time. I suspected they may have gotten the wires reversed, but the results were exactly the same with the new ignition switch.

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Ok I realize Im not quite in the loop on all this...but I have a sincere question:

 

Is it possible to bypass all that safety stuff? How would you do it? Would it be simple or difficult? Reason I ask is that in all my years riding dozens of bikes, I never killed myself either starting in gear with the clutch out, or trying to ride off with the sidestand down. Do we REALLY NEED all this stuff on the bike? I mean, were not beginners.

 

Only once or twice in 40 years of riding have I left a sidestand down when riding off, and it nearly got me. This was on a Suzuki GS 750. My Harley and most Harleys dont have any of this stuff and somehow we get along fine on them. They DO have a sidestand thats designed to foldup if you ride off with it down.

 

Mine is working perfectly now, but say in 5 or 10 years, I want to bypass some or all of this, has anyone ever tried?

 

I made a simple, albeit not ideal, solution to my problem. By attaching a leather loop to the clutch lever, I can pull in the clutch, put the leather loop around the handgrip and it will hold in the clutch and the bike will run while on the sidestand. I can then help my wife zip up her chaps and allwo th ebike to warm up. However, since the clutch is pulled in, if something (or someone) hit the gear shift, the bike would take off. :doh: Like I said, hardly an ideal solution. Plus, when something is not working correctly, and I don't know why, it makes me think it could be a symptom of a larger problem. :confused24:

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Ding Ding Ding - we may have a winner! Assuming I have correctly understood your symptoms, it seems likely that you have a open diode between the light green and blue/yellow wires on in your Starter Cutoff Relay. To test that you will need to disconnect the relay and measure the resistance between those two pins with an ohm meter set on the x10 scale (or use the special diode check scale built into most modern digital meters). With the negative lead connected to the Lg (light green?) pin on the relay and the positive lead to the L/Y pin (??? did you mean Blue/Yellow?) , you should have some measurable resistance (the exact amount is unimportant). If you reverse the leads, you should read infinite resistance (same as when the leads are not connected at all. If you read an open (infinite resistance) both ways, then the diode is burned up, as if it is not there at all. This could have happened if one of the wires that came loose shorted out.

 

If you DO find a bad diode here, then you should also track down and check another diode in the side stand switch circuit. On the schematic it is number 12 and only labeled as "Diode", connected with a two-pin plug to the side stand switch circuit using blue/white and blue/yellow wires (blue/white from the switch, blue/yellow to the SCR). I have no idea where it is, but if something fried the diode in the Starter Cutoff Relay, it could have possible shorted out this diode also. Right now I think you may have been lucky you didn't fry the Igniter, so best to check everything to keep that luck!

Goose

 

WOW, I think I burned out a diode in my brain just reading all this. You do seem to understand the problem. (I was afraid I would not be able to explain it adequately) Now - where on the bike would I find the Starter cut-off relay? Are the diodes separate from the relay (like an in-line fuse) or an integral part of the relay itself? In other words, do I replace the relay if it's bad or do I have to track down this malcontent diode somewhere in the speghetti of the electrical system?

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If you can get a wiring diagram to me I can walk you through how to check these switches. I just picked up a Venture this week. I can use my bike as a reference. What year is your bike?

 

Thanks, Randy. My bike is a 2000. But I have no idea where to find a wiring a diagram, other than the one that's in my Clymer manual. I'm not sure that would suffice. The switches do not seem to be the problem - there is a new side stand switch, clutch switch & ignition switch. And the problem remains - gotta be something else. Well............PROBABLY something else.:fiddle:

 

Monty -

It shouldn't take off as long as the clutch is in...if it's adjusted correctly.

You are correct and my fear was incorrect. As long as it's on the side stand, the engine kills as soon as it gets dropped into gear - even with the clutch lever held in by my nifty leather strap. :banana:

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WOW, I think I burned out a diode in my brain just reading all this. You do seem to understand the problem. (I was afraid I would not be able to explain it adequately) Now - where on the bike would I find the Starter cut-off relay? Are the diodes separate from the relay (like an in-line fuse) or an integral part of the relay itself? In other words, do I replace the relay if it's bad or do I have to track down this malcontent diode somewhere in the speghetti of the electrical system?

I haven't tried to analyze the test results you posted yet in response to my questions, but even so, I am virtually certain the problem will turn out to be the diode I pinpointed in the Starter Cutoff Relay.

 

In most of my post I used actual wire colors to help you when looking at the bike (e.g., light green and blue/yellow), but when I gave you specific instructions on how to test the diode inside the SCR, I used the pin identifications that you will find on the Yamahaha schematic, since that is the only way you can be sure to find the correct pins in the plug on the relay. The second page of the schematic shows you plug pin-out diagrams. Lg is the pin for the light green wire, L/Y is the pin for the blue/yellow wire, but Yamahaha's code for Blue/Yellow is L/Y.

 

I don't know for sure where the Starter Cutoff Relay is, but I'd bet it is under the seat behind the center battery cover. I thought I'd let you ferret it out (there is only so much I'm gonna do to solve this for you unless you really beg! :rotf:).

 

The SCR actually hast two different realys in it (the starter cutoff and the fuel pump relays), along with 5 diodes. I suspect it is an expensive part, but I have never priced it. There is probably no way to actually fix the part if that diode is open, but if the price is too outlandish, I could tell you how to add a replacement diode to the wires outside the SCR. It all depends on how much you think you can handle in making electrical mods.

 

Before I go any further and speculate on possible fixes, you need to test the diode and verify it is bad, then we can talk about what to do next. :080402gudl_prv:

Goose

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I don't know for sure where the Starter Cutoff Relay is, but I'd bet it is under the seat behind the center battery cover. I thought I'd let you ferret it out (there is only so much I'm gonna do to solve this for you unless you really beg! :rotf:).

 

The SCR actually hast two different realys in it (the starter cutoff and the fuel pump relays), along with 5 diodes. I suspect it is an expensive part, but I have never priced it. There is probably no way to actually fix the part if that diode is open, but if the price is too outlandish, I could tell you how to add a replacement diode to the wires outside the SCR. It all depends on how much you think you can handle in making electrical mods.

 

Before I go any further and speculate on possible fixes, you need to test the diode and verify it is bad, then we can talk about what to do next. :080402gudl_prv: Goose

 

 

Alrighty then - I'll see if I can find it & then test it when I have some time. That won't be for a little while, tho. Thanks again Goose, for all the brain energy you've expended so far. I'll save the information on testing the relay and get back to you when I have some results.

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  • 1 month later...

I located the Starter Circuit Cutoff Relay - it's to the left of the coolant tank, behind the inner cover. Pretty much right where you said it'd be. Damn, you're good!

 

I removed it, located the blue/yellow and light green terminals on the plug and marked that on the relay (terminals) and set my VOM meter to OhmX10 and ............... And I got nothing - the needle didn't move even when I reversed the leads. So that means..................time for a new relay? :think: Or I did the test wrong? I double checked to make sure I had the correct terminals & I'd bet your life I got them right.

 

And since it seems to be a sealed, plug & play type unit - there's no replacing diodes.

I located one at BikeBandit - it's not horrible price-wise about $47. :fiddle: Although I'm not so sure about their diagram labeling being correct.

 

I hooked eveything back up and she starts the same as always - with the clutch in. I await further instructions.

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This is the link to the on-line micro-fische for the electrical system at BikeBandit. The diagram was the same at Cycle Parts.

http://www.bikebandit.com/houseofmotorcycles/yamaha-motorcycle-royal-star-venture-xvz13tfm-2000-electrical-1/o/m7566sch121444

 

Check out part #41. I removed the relay according to the Clymer manual - the SCCR was under the seat, behind the inner cover, next to the coolant tank and it looked just like part #41 on the diagram. But part #41 is listed as "RELAY ASSY, FOR SIDE STAND".

There is no Starter Circuit Cutoff Relay listed and there is no description of the relay or it's function other than "for side stand".

 

Based on the appearance & location on the diagram, #41 would seem to the correct part. But I'd rather not make a $70 mistake...........again. (the starter relay was $47)

Thanks for your input

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OK, I assume, you have the New Relay, and are trying to decide which one installed on the bike, is same as the one in your hand ???

 

Part Number!!! --- Compare Part numbers, should be stamped on the side of New and Old relay !!!

 

Also, I believe the Plugs on Will only fit on the correct relay.

 

Compare the Pin layout of plug to relay, as a double check,

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