Test VN750 Reserve Lighting Unit?

[Ol Poop]

Does anyone know of a testing procedure on a VN750 Reserve Lighting Unit like you can do on the Terminal Block?

I'm having problems with the headlight circuit on my 2003 VN750. Everything else works except the headlight and the Hi-Beam Indicator. Neither upper nor lower beams are getting any juice and the headlight fuse has voltage on both sides of it. The fuse has not blown at any time.

I recently let my battery go dry and caused a lot of testing to determine that the stator and R/R were not damaged. I may have damaged something in the lighting circuit while I was at it. All of the charging-starting-running-lighting circuits are operating fine, but I don't have any voltage at the headlight. The Terminal Block ohms out fine, but I don't know how to test the Reserve Lighting Unit.

I tried another RL Unit off of a '94 parts bike without any change, but, I don't know if it's a good one either.

Any help would be appreciated.

[QKENUF4U]

if i remember right this is one of the models that run the headlight power supply thru the starter button. ive had 2 bikes come in w/ your same problem. try this, take the starter button and move it around a bit with your finger , this MAY pop the light on/off or not do anything at all if its totally shot. ya need a manual to get the proper procedure to check it at the harness, i dont remember off the top of my head,sorry.

[Ol Poop]

QKENUF4U, you were right on the money!

I started the bike, no headlight. I pushed the starter button in again while it was running and let my thumb "slide" off of the side of the button to let it snap back out. The headlight came on.

I killed the bike and when I restarted it, the headlight was out again until I "snapped" the start button a couple of times. Now that I know where the problem is, I can fix it.

I suspect that having a throttle lock on the bike has caused me to continuously push the start button in at an angle instead of straight in. I've probably tweaked it a little somehow.

My frustration level is back down to a manageable level now, thanks to your reply. I was near the point of throwing wrenches. I thank you (and so does my wife).

[QKENUF4U]

EXCELLENT MAN !!!! guess thats y im paying 18k in loans after going to school at MMI (graduated now to be exact)
youll have to replace the switch assembly on the bars unless you want to get into the assembly and play with it a bit. up to you.
good luck

[1Adam12]

Originally Posted by QKENUF4U

EXCELLENT MAN !!!! guess thats y im paying 18k in loans after going to school at MMI (graduated now to be exact)
youll have to replace the switch assembly on the bars unless you want to get into the assembly and play with it a bit. up to you.
good luck

Wow QKENUF4U, Talk about opportunity cost to get educated! Did you have a job lined up prior to exiting school? Is MMI's reputation out there good? I have heard from others back east that they were not happy with the program for various reasons. I personally would take the classes just to work on my own bike if it were closer to me and had more time.

[QKENUF4U]

[/quote]

1. Wow QKENUF4U, Talk about opportunity cost to get educated!

2. Did you have a job lined up prior to exiting school?

3. Is MMI's reputation out there good?

4. I have heard from others back east that they were not happy with the program for various reasons.

5. I personally would take the classes just to work on my own bike if it were closer to me and had more time.[/quote]

1. ya wanna play, ya gotta pay

2. no but ive been in and out of the bike business since i started school back in feb. 03

3. it good here in town since its here IN town.

4. i think the people *****ing are people who thought "I WILL KNOW EVERYTHING THERE EVER WILL BE TO KNOW ABOUT BEING A BIKE MECHANIC AFTER ATTENDING SCHOOL HERE !" thats just stupidity on their part cause experience is the only real teacher in this business. you cant go to school and dwell on the bad stuff, you cant sit there and ***** about this,***** about that. doesnt do you any good to get worked up over the politics involved with this or ANY other school. i went there to learn all i could and thats what i did. i worked as and entry level tech at a local bike hop for 3 months and learned something NEW everyday. this is def. a tough town to be a bike mechanic in since the school is here and the kids will work for less money. (the pay is better here than it is back east though)

4. thats a hell of a bill for just working on your own bike. i have been to phoenix for school before (90/91) i used to be a computer aided draftsman, did that for 12yrs, had a bike accident that about killed me and said to myself "this **** is for the birds,im tired of getting fat,sitting in front of a computer,burning my eyes out and getting no exercise!!" so after my accident i said "im going back to PHOENIX and back to school (MMI) so that i can be happy with my life !!" i hate the humidity and winter back home in PA. you can have that garbage. the last couple years i would have been lucky to put 3k on the bike with all the rain weve been having.

well anyways thats my story.

[Ol Poop]

Maybe I started celebrating a little too early. While the Starter Switch button DID have an effect on the headlight circuit, it wasn't as we thought.

I tore into the Starter Switch and didn't find anything wrong with it. It's simply a push-to-close, spring-loaded switch. It only has two wires going into it to activate the Starter Relay. The only other two wires in the right handlebar control unit goes to the Engine Stop rocker switch that opens or closes the Ignition Coil circuit.

Actually, what was happening when I was "snapping" the start button and getting the headlight to come on, I was actuating the Starter Relay and Starter Motor momentarily while the engine was running. I've gotten the headlight to come on enough times this way to know it will do it repeatedly.

I've looked and looked at the wiring diagram in the book, and I can't figure out how bumping the Starter while the motor is running could cause the headlight circuit to begin working, unless it has something to do with the Junction Box or the Reserve Lighting Unit. The Starter Circuit Relay is in the Junction Box, while the Starter Relay is a separate unit. The Starter Relay tested good according to the bench test in the book. The Junction Box also tests good according to the book, but it's only a fuse circuit test.

After I get the headlight to come on and I use the Engine Stop Switch to kill the motor, the headlight stays on just as it's supposed to do. Once, while the headlight was on and the motor off, I wiggled every wire that I could think of, and tapped on all of the component boxes associated with the headlight and starter circuits, with no effect what-so-ever. Once I turn the Ignition Switch off, the headlight goes off (like it should), but won't come on again after the engine is started (like it should), until I bump the Starter Switch button again a few times.

Any more ideas?

[woundwort]

I would guess next step back from switch is the starter selenoid???

when I key on I get no light.
When I hit my starter the light comes on whether the bike starts or not.

It's gotta be in the start circuit.

[Ol Poop]

Thanks woundwort. I think you're right (almost).

From what I can tell by the schematic, from the Starter Switch (start button), the circuit goes through the "Starter Circuit Relay" in the Junction Box, and then on to the solenoid (Kawasaki calls the solenoid a "Starter Relay"). The Starter Relay/Solenoid tested ok.

It's gotta be in the start circuit.

I could agree with this part, if I knew more about that danged "Reserve Lighting Device". Not knowing exactly how it fits in with the circuit is what's bothering me. I don't see any schematic for it in my book to see what's in it, but the headlight circuit runs through it. If not for this "mysterious" component, I would tend to think that letting the battery go dry earlier caused an increase of current through the little relays within the Junction Box and warped one of them to the point that an extra little "spike" of current flow is needed to pull the relay tab closed and complete the headlight circuit. Even though I never popped a fuse, the increased current for an extended period of time could have caused some damage. I was on the road to Sturgis when all of this stuff began happening. Could be the relay in either the start circuit or the light circuit, or both. They're sealed in the Junction Box, so they're not accessible.

In the Junction Box, the Starter Circuit Relay and the Headlight Relay interact to shut the headlight off when the Start Switch is activated. But is there anything in the RL Device that could be at fault? I sure wish I knew more about that thing.

I'm leaning toward replacing the Junction Box unless somebody comes up with something else. I just hate to buy one and then find out it was the RL Device that was bad. I feel like the headlight circuit wiring is fine, thanks to this forum and QKENUF4U for suggesting that I fiddle with the start button. At least now I can get the headlight to come on and stay on. That's narrowed it down to something keeping it from coming on like it's supposed to do, and leads me to think it's a relay. Without you guys, I would still be pulling the tank and stripping wiring harness cover trying to find a bad wire.

[QKENUF4U]

im still thinking its your starter button assembly. there is nothing special about the wiring. (contacts/springs) see if you can find the relay (RL) that you are talking about. do they NOT tell you about testing the starter button assembly ?
are you sure the headlight always came on when you turned the key on ? if it did and you wiggle the starter button and it comes on then theres your problem. if it didnt come on with the key then there is no problem.
i have never heard of RESERVE LIGHTING though, are you sure thats what its called ?
if you wiggle the button WITHOUT getting the starter to turn over does the light come on ?
as for the junction block i dont see how you hitting the starter button would effect that. maybe do the wiggle test to all the wires going into the box and see if that effects anything.
good luck

[Ol Poop]

QKENUF4U,

I know where you're coming from on the starter button assembly. But on this particular model, the circuit splitting apparatus to kill the headlight load when the starter motor needs the juice, is located either in the Junction Box or somewhere else. In the Junction Box, it's a transistorized relay and diode that gets power from one of the stator leads when the motor is running, or from the "Reserve Lighting Device" when the motor is not running. Therefore, there's nothing to the start button except a simple push-button switch.

The "RL" that I am referring to, is the "Reserve Lighting Device", not a relay, and I found it as a separate component bolted to the battery box along with the other electrical components. It has a 6-pin connector to the wiring harness. I just can't find anything in the book about testing the RL Device, or how things are supposed to happen within the device.

There is a test procedure for the Start Switch (button), but it's simply ohming out an on-off switch.

When you first turn the key on, the headlight on the VN750 does not come on by design. From what I can tell from the schematic, it won't come on until it either receives AC current from the stator (motor running) through a diode (rectifying it to DC) to activate the Headlight Relay, or it gets a feed from the "Reserve Lighting Device" (motor not running) to activate the Headlight Relay. The headlight is powered by the engine while the engine is running. When the engine is NOT running, the only other connection (through a diode) that I can see to close the headlight circuit, is a connection to the "Reserve Lighting Device". That's what makes me want to know what's supposed to happen in there.

But, I just thought of another possibility. What if the stator is working intermittently. Like, maybe sometimes it's pumping out good AC voltage, and sometimes it's not? Ever hear of a stator that works "part-time"? Or only works after a certain length of running time? Maybe my farting around with the start button is not the key to when the headlight begins working? What if it's lighting up the headlight when the feed from the stator is established, and I only THINK that I've caused it? I've checked the stator leads with the leads disconnected from the wiring harness, but I only looked long enough to get a reading (which was a strong 50+ VAC across all three of them). I guess I could put a meter on the stator leads (two at a time) while they're still connected, and see if I get good AC readings between all of the leads for an extended time. That's something that I haven't done yet (the danged pipes get so hot that I finish the AC output test as quick as I can ).

[QKENUF4U]

if you have no light you may have a bad ground somewhere. check your schematics and see where the grounds are.
i still think your RL is actually a relay, it has to have power on one side to close it and supply power to the headlights. you could find the power in/power out tabs , maybe put a jumper wire (paper clips with your volage meter attached) from one to the other and see if your lights come on.
the only time i can see a stator being bad is after it gets hot and goes OPEN (break in the wire that opens) if your getting 50+amps then your good to go. might have to check it when its hot to make sure its not doing the above.
did you do the manual check at the starter switch ?
good luck. ill keep throwing ideas at ya if i can.
later
lance
.

[Ol Poop]

Yea, it could be a bad ground causing the problem, but it wouldn't appear that bumping the starter would have any effect on that either. It may just be a coincidence that the headlight comes on when I'm fiddling with the start button. There could be something else going on that I (we) haven't considered yet. I think I have some more testing to do to rule out some of the things that we've already discussed.

I'm sure that the Reserve Lighting Device has relays in it, and probably some diodes to direct the current. Damaged parts in this unit might keep the headlight circuit from working properly. That's why I'm still looking for a schematic for this device, or some known test procedure. Hopefully, someone out there has one.

To tell you the truth, no, I didn't do the repair manual test on the Starter Switch when I had it apart. Since I'm not having a problem with the starting circuit, and the Starter operates every time that I push the button, I didn't see the need. It's a push-button switch that either works or doesn't work, and this one is working.

Thanks for your input on this. Keep throwing your ideas my way. I would really like to pinpoint the cause of this problem. I could start replacing components at any time, but I hate to ruin the educational value of the situation. I may resort to that for a solution later, but I'm not ready to throw in the towel just yet. It's like working a puzzle when I know the answers are in the back of the book. The whole idea is to figure it out for myself. I need to learn more about these systems, and now is as good of a time as any. If I've learned anything in my 52 years, it's that generally I'm not as smart as I think I am, and can always learn something new. This one's got me stumped for now, but I'm going to keep plugging away at it for a while...

CD

[QKENUF4U]

like i said above, are you sure the headlight always came on with the key ? it sounds like theres no problem. if you hit the starter button the light comes on right ? or is it intermitently come on ? maybe try starting the bike and then wiggling the starter button ?
as for the relay, it may be in that junction box but its still a relay. it may be getting tired and not energizing/closing all the time like it needs.
find the wires that feed it power (POWER IN) and find the wire/s that feed out (POWER OUT) if you have power in and NO power out then thats the cause.
its a puzzly like you said. you need to just work your way backward or forward on that path and find out where the break is. break it down into small sections eliminating one thing at a time.
also test that starter switch like the book says. there was nothing special about the same switch on the bikes that had the same problem that ive diagnosed.
good luck

[Ol Poop]

I talked to a Kawasaki Service Technician in Oklahoma City on the phone, to see if he had a schematic for the "Reserve Lighting Device". He's never seen anything on it, other than what's in the book. He pointed out what I had read earlier in the book about the device.

The Kawasaki Service Manual says on page 15-37: Under the heading "Headlight Reserve Lighting System Inspection", the final sentence reads: (Quote) "*If all wirings and components other than the reserve lighting device check out good, the device is defective."


No sh**??? LOL! I was amused to read that piece of wisdom in place of instructions about a testing procedure. I guess that's one way of determining if it needs replaced alright, but there ought to be another way. How do you check out the wiring coming and going from the Reserve Lighting Device, if the device is defective and won't let current pass? I guess it means to change everything else first, before deciding that the device is actually defective, when you could have tested the device and found it bad in the first place.

Nah, there's got to be some way to test the device with a multimeter. Somebody's figured it out. We'll just have to wait until they read this thread.

CD

[QKENUF4U]

well thats not always true. there are certain electical components on these bikes that you cant test. a multi-meter just wont cut it.
but my point is, do you have power TOO THE RL UNIT and if you do , do you have power OUT OF THE RL UNIT if not then theres your break/malfunction in the system.
good luck

[Ol Poop]

The Junction Box wasn't the problem. It's something else.

[QKENUF4U]

Originally Posted by Ol Poop

I started the bike, no headlight. I pushed the starter button in again while it was running and let my thumb "slide" off of the side of the button to let it snap back out. The headlight came on.

I killed the bike and when I restarted it, the headlight was out again until I "snapped" the start button a couple of times. Now that I know where the problem is, I can fix it.

this still tells me that the starter/kill switch assembly on the handle bar is bad. its EXACTLY what i saw at the shop while working there.

[Ol Poop]

Boy, you've got me! I've disassembled the right handlebar control again and looked at everything there. I don't see a thing wrong with the two simple switches. One's an on-off rocker switch and the other is a push-to-close button. Unless I'm not seeing something, all of the circuitry that shuts the headlight off while the starter motor is activated must take place somewhere else.

Please don't be offended, but I just can't see anything wrong with the starter/kill switch assembly. I must be missing something. I need more help. I can take the push button start switch completely apart, including the spring between the contacts, and everything appears fine. The kill switch only has two wires going to it, and appears to be a simple on-off switch. Nothing appears burned, warped, or out of the ordinary.

I even went back to what woundwort had said earlier. He thinks it must be in the start circuit, and he may be right, but I haven't figured out where. I can't get anything to not operate correctly other than the headlight. And the headlight and hi-low indicator lights work perfectly after I've bumped the starter a couple of times with the motor running.

I've got a '94 parts bike, and have substituted the Starter Relay, Reserve Lighting Device, and Junction Box onto this '03 model, without any change. I bought and installed a new Junction Box without any change.

I started chasing voltage through the components and everything has checked out good, until I ran into a different wiring color in the Junction Box than was shown in my book. My book covers older models, so they must have changed the color code in the newer ones. Before I go any further, I'm going to get an '03 book.

If anyone has any more information on this problem for this slow learner, I'm running out of ideas and can use all of the help I can get.

CD

[Caelum]

Hi Ol,

I've the exact same problem with a 85 GPz900R. Started happening after I got caught in the rain. A friend and I pulled the entire wiring harness out and did continuity testing, exchanged out solenoids etc. Everything in perfect (for a 20 y/o) order. If I pump the start switch a few times light comes on and stays on... Again same as - narrowed down to either switch problems or the Reserve unit. If you've switched out the RL then I'll jump straight to swapping out the starter switch.

Buggering thing isn't it! As my friend said - I hate electric's....

Caelum