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Discussion Starter #1
Ok Fellow Strat jocks. Got an electrical issue, pulled bike out to wash, didn't notice that headlights where not on, washed it, then realized no headlights or accessory lights, or hi beam indicator are also not working, checked all fuses, and replaced the 20 amp for headlights, fuse in headlight bowel for accessory lights. fuses good, next checked headlight relay, unbolted fender to move it back to get to the #52 headlight relay. What a pain. Anyway checked relay, it's working fine, ordered a new relay, installed same problem. Broke out the DVM, I have 12 volts on the connector in headlight bowel on green wire return from dimmer switch. still no headlights, removed relay, put a battery positive on the lead going to green wire from relay switch socket, both headlight hi/low work, also accessory light works. So wiring from relay is good to headlight/handlebar switches. Also tested each bulb in headlight, ground is good. Relay is clicking fine once engine starts but no headlights. I don't have any other ideas, just hoping it's not the ECU that sends the engine start signal to turn on the lights. I suspected to find a burnt wire, or corroded pins in connectors, didn't fine anything abnormal. Any idea's. Everything else is working normal. I'm stumped. Did learn that the schematic does not show the various connectors in the headlight bowel. They are easy to id, with wire colors from manual, also between the handle bar switches to main connector in bowel. Help, can't ride the beast without lights.
 

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If the relay is clicking on start, I wouldn't think the ECU is at fault.
In other words, the relay is getting the signal. That's what get out of what you are saying.
I have somewhat a similar problem. Every time I wash the bike my passing lamps stop working for a day.
I suspect in my case the switch gets wet.

At one time a had a problem with the headlamp. It worked fine when out of the bike but when you jam all that wiring into that cramped bucket, something would disconnect and I'd have to pull it apart again.
 

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everyone always forgets the ground connection - if you have 12V to the headlight connector and the light is not on, then the ground wire or connection to the frame is broken or corroded.

Most vehicles use the metal frame of the bike as the power return 'wire'. It cuts the number of wires required on the vehicle in half.

Sometimes its easier for a circuit to use the ground return wire as the switch, so you can have 12V to the light, but if the other side is not being switched to ground it will be off.

Notably horns on cars are usually wired this way - Im not sure why, they run 12V right to the horn, then run the return(ground) wire up thru the steering column, and the horn button connects that wire to ground on the steering wheel.

When a motorcycle wont start, very often it is the ground wire from the battery to the frame, which normally bolts to the frame where you cant see it.
 

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Discussion Starter #4
Good points about the grounding issues, I do get a good beep when checking between wiring black ground wires to the headlight bowel steel, but now wondering if there is another ground path going to the bike chassis. This has to be the culprit as every wire that I checked was in good condition, no corrosion or burnt spots, I was surprised that it's in such good physical condition since it's an 07 model, I purchased it in 2011, and have about 40K on it now. I'll find it and let everyone know what I find. Thanks.
 

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Like KCW says, the bucket needs to be grounded. Have did you try running a ground wire directly from the negative post on the battery and ground out the bucket? Inside the bucket there should be a tab welded to the bucket with a green ground wire attached. Maybe it got disconnected.

Im not sure why, they run 12V right to the horn, then run the return(ground) wire up thru the steering column, and the horn button connects that wire to ground on the steering wheel.
Most likely simplicity. You only need to run a short hot wire to the horn and one ground wire from the horn button (steering column) to the horn rather than run a hot wire to the button and then run it to the horn from there as well. Also, I remember the older cars that wire would short out due to the rotating of the wheel and the horn kept blowing. You could cut that wire and stop the horn instead of blowing fuses.
 

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Discussion Starter #6
Ok guys, I tore into the headlight bowel last night, gently pulled all the wire clips out towards the front, and do not see any kind of ground connection in the bowel, looked all around the rear and underneath the bowel, there are no green wires anywhere other than on the various connectors in the bowel. I have checked wiring from hi/low switch, and also the cruise light accessory wiring above the start button, had both of these switches opened up on the bars, get good continuity everywhere I need it. Have not found anything corroded or burnt. I am getting very familiar with the wiring method on this monster. I have the signal from the ECU that sits around zero volts then goes a bit negative, like a half volt when the engine starts, have constant 12vdc on the other relay coil wire. Good power to lights when I jumper across the relay connections with a wire with male spade lugs, both headlight and accessory lights come on fine. I do have good ground connectors in each of the cruising lamps, did find both 5 W bulbs blown, replaced them with 168's, The 192's someone else mentioned are only about 3Watts each. The main 35 watt bulbs in these lights are fine, and bright. I have also ran a temporary ground wire from the bowel to a ground point near the battery under the seat. still no luck. The lights will not work when I start the bike. But everything else is working fine. I don't really suspect the ECU but am wondering about it.
 

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There was a thread a few months back about someone having wiring problems on their bike, and the question came up whether or not the motorcycle headlight comes on when you first turn on the ignition key, or if it does not come on until after you crank the starter and the engine starts.

On the older Vstar bikes the headlight is always on when the key is on. At some year they changed that on different models so the headlight would stay off (for whatever reason) until the engine was started - then it would stay on until the key is turned off.

So... if that is the case on your bike there is obviously some circuit or sensor that decides when the engine has started up, and it switches on the headlight.

I dont know what that circuit is, or how it decides the engine has started, but that seems to be the only thing left. If that is how the headlight works on your bike then something must have failed, and the ECM does not think the engine is running.

Or maybe this is really easy, and you have been debugging your headlight with the engine not running, in that case - get your motor running and see if the head light come one?

If you look into this you should be able to figure out which year Yamaha put this "feature" on your model bike. I have a 2005 650 and my headlight is always on. We did sort of a poll and people were posting which way their bikes are wired. If you search on 'headlight' you might be able to find that.

Sorry I dont have all the details, but hopefully this will point you in the right direction.

Maybe if the ECM is wacked out you could reconnect the enable wire to the right place, and the headlight would always be on when the key is on?
 

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Discussion Starter #8
Yes, my headlights only come on once the bike is started, and while testing stuff in the circuit, I am constantly starting the bike, the ground paths for the two light circuits are not simple grounded units, they each have a separate ground going back through the big harness running down the frame below the tank, stopping just in front of the battery area. I'm still looking. Don't really want to put this whole monster back together just to take it to a shop so they can take it apart again lol. Now my accessory light bar does have an individual ground in each small bowel. But ground and red (hot) from accessory switch is in a dual connector in the bowel, so this set of lights actually has two ground points. You did give my some good places to look. Maybe someone else will pop a memory related to this odd ball.
 

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I have the signal from the ECU that sits around zero volts then goes a bit negative, like a half volt when the engine starts, have constant 12vdc on the other relay coil wire.
Are you saying the brown wire is hot? It should be. From what you say and from what I see on the wiring diagram, the headlight side of the relay seams to be working fine, ground and all. I think the problem leans toward the actual relay side of the relay. It looks like you should have a steady hot side, when the key is on, to the brown wire. The relay would be energized, turning the lamps on only when the ECU supplies the ground to the Yellow/Black wire. You say you are getting .5 volts w/engine running. I (just guessing) wouldn't think that is enough to make the relay work.

#79 is the 'signaling system fuse'. If that fuse is OK, it would send '+' to the relay side of the relay and also '+' to the horn (#50). If the horn works, that eliminates the fuse but you still need '+' on the brown relay wire.

Maybe supply '-' to the Y/B wire on the relay and see if the lights work. I don't know what the effect would be to the ECU, if it would hurt it or not but I'd try it.

You may end up putting a ground switch in to kill the lights when starting. WHY-OH-WHY didn't they just put a normal starter button in like other bikes where you press the button and it brakes the connection to the lights and returns it when the button is released?
 

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I would not back feed the control wire from the ECU to the relay.

If the control side of the relay works by keeping the high side on 12V all the time and the ECU grounds the other side to make the relay close (and turn on the lights), then disconnect the ground wire from the ECU and ground it. But dont ground it or put 12V on it while its still connected to the ECU, because you will be back-feeding an output from the ECU with power (or ground).

If the lights go on your relay is good, and the ECU is confused and does not think the motor is running when it is.

If you just ground that wire all the time, the headlights will always be on when the key is on, like about 50 million other motorcycles made since 1965.
 

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^ Kinda what I was saying.
If the problem can't be resolved and everything else works, a switch is cheaper than a ECU.
Either provide '-' to the relay control or '+' to the head lamp side of the relay.
That way the lights can be turned off during start-up.

If you just ground that wire all the time, the headlights will always be on when the key is on, like about 50 million other motorcycles made since 1965.
On those bikes, there are 2 plates, one at the bottom and one at the top. When the start button is pressed, the bottom plate closes the circuit in the starter solenoid and at the same time the top plate moves away from the lighting contacts and that circuit becomes open and the lights drop out. When the start button is released, the top plate closes the lighting circuit again.

I'm guessing that Yamaha is using a relay due to the type of starter switch.
 

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Discussion Starter #12 (Edited)
TimBucTwo, I like this thought direction, as it does make sense, been looking at the starter relay next to the other relays in front of the fender, I did manage to pull diode #1 out and it tested fine. can't find diode 2. It shows it's right next to the headlight relay, but all I have is the EXUP motor unit, nothing else there except the starter relay and fuse, 15 amps. I also found info on the other Star bike forum that mentioned the battery, hmmm, I checked mine with a good dvm, and because the bike has been started for testing so many times, it's below 12 vdc, got it on a high tech charger now, will try again once I get it back to normal, but also realized this battery is my original battery from the dealer. I think I'm going to find me a new battery also, since digging around in the electricals for the past two weeks, you never know. I also picked up a standard use relay, with socket and a nice LED lighted switch just in case I have to bypass the stock non working parts, I get both headlights and accessory lights when I plug 12 VDC direct into the green wire on the socket for the headlight relay. I'll keep you guys informed once I get this issue figured out. I won't ride it without headlights.
 

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Discussion Starter #14 (Edited)
I see that harness above, mine looks clean, this is the second fuse I checked, tried isolating also, removing things that can be unplugged, but still nothing found, I'm looking tonight at the starter relay, but don't understand totally about the second set of contacts used to remove power for the lighting while starting, is this supposed to be including in the actual start relay or in the handlebar switch assy on right handlebar, or part of the starter switch ? I keep learning more and more about this beast's electrical system. The diodes I'm talking about are separate shown in the schematic, as Diode 1 and 2. One is wired near the starter relay, and can't find the diode 2. All the relays have internal diodes, I think to keep voltage feedback from going the wrong way, and or to short out the magnetic coil pulse when the relay opens. It's been over 40 years since I was in electronics tech school, that's what I did for the Navy and still do today. That's part of the reason I'm so frustrated with this bikes electrical system. Not much is explained, don't know why it was engineered this way. But I'm sure some engineer somewhere knows why, we'll never know. I know motorcycle and automotive electricals can be a mystery. Oh and I got a good charge on my battery, normalled everything up this am, and still no lights. Battery looks good. I will be on the lookout for a replacement anyway. This battery is a sealed gell cell, never had any problem with it since I purchased (bike) in 2011.
 

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Discussion Starter #15
I don't know if I mentioned what I did find in the passing lamps, the small 168 bulbs were both blown, but the main 35 w bulbs where good. How that happened, don't know, replaced them. Found a tiny bit of water damage (rust) in the bottom of both bowels, same with headlight bowel, just a bit, and noticed very light chroming on the inside of each bowel. I suspect the passing lamps chrome will not last very long as they are already showing some tiny rust pits.
 

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A standard lead acid battery will last 4 years (a $30 battery). If you buy the super duper extra special lead acid battery it will cost twice as much and last 5 years.

If your battery is from 2011 its way past its expected life. Even still, if the battery will hold 12V while the engine is running, the headlights should come on.

I dont remember if you have the factory service manual for the bike - for some Vstar bikes you can find it online as a free PDF download. The schematics are in the back of the service manual, but...

they show all the connections for every part and component and how they are wired together, and what color the wires are, but they do not show you what is inside the modules. For example there is no drawing of the inside of the relays, or whats going on inside the ECM, and there is no explanation of what each wire (signal) is for - so you have to figure it out yourself. They do have a trouble shooting tree, for example: if your headlights dont work, replace the fuse, then replace the relay, then replace the ECM.... but that is assuming you are a Yamaha shop and you have all those parts on hand to test one by one, and see which one fixes the fault.
 

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I kept blowing the little 5w bulbs in the passing lamps also so I replace them with LED's and no problem so far.
While I was in there I upgraded to 55w halogens up top. That extra wattage is what fried the harness. This time I didn't replace that stupid metal plate that makes it almost impossible to install the headlamp. Light goes right on in without it.

If you want to go with a new battery, I suggest Shorai LFX18A1-BS12 Lithium Ion. I have had it for several years now and still going strong. $$ up front but last 3 times or more longer.

The point I was making earlier is that the start button is just that on these bikes. They don't effect the lighting. There is a diode in the relay, I think it has to do with the way the head/passing lights stay on when the kill switch is used to stop the engine.

I popped my seat off and took a look at the fuse boxes. The one marked 'Headlight' has a 3 on it. It can't be a 3 amp fuse can it? Its the one more toward the rear of the bike in the bigger fuse box. You say you checked this fuse?
 

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3A * 12V = 36Watts, if that clears anything up

a 55W lamp would need at least a 5A fuse.
 

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3A * 12V = 36Watts, if that clears anything up

a 55W lamp would need at least a 5A fuse.
The headlight fuse should be a 20A one according to the manual, which is the biggest fuse barring the main fuse, which is 50A.
The 3A one is the one for accessories. Unfortunately, for many accessories that is not really all that much.

HTH, kind regards
 

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Discussion Starter #20
Yes I have the paper manual, never purchase a vehicle without the manual, I use the fold out schematic in the back, and each night I have dug deeper into things, last night ran through the built in diags, don't have any codes showing on display but tried it anyway, it's confusing at first but does test all the major components, just not the lighting circuits. I'm still looking for info on the headlight bypass while starting ? a few have mentioned this, the starting relay only has the normally open connections, so has anyone taken the start switch assy apart and could shed some light on this, I'm going out to the shop now to see how the handle bar switches are wired. Would be nice to find a corroded contact in the start switch area. First time I glanced in this one, I was only looking at the accessory switch. Oh and since all of these lights run off the one green wire on the headlight relay, including the highbeam light indicator in the instr panel. I'm thinking my wires are fine. Relay works, all switches work, each light tested with a jumper across the relay socket connections (without the relay) turn on all lights as expected. My mystery is the signal from the ECU that is on the ground side of the relay coil, the other side is always at battery voltage. I didn't put anything into this wire to the ECU, don't want to further any damage in case this is the culprit. I'm adding an extra relay and switch leaving the original wiring intact, and can be normaledl up once/if I find the actual cause. Keep tossing out the idea's guys, I just can't handle taking this monster 50 miles to the dealer.
 
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