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Discussion Starter #1
I wonder how many Wings beside mine have a dim left High Beam Headlight?

Through a recent research that Fred did at my request, we find that Honda has done something very peculiar in the 2002 and subsequent models of the GL 1800.

The power for the Left high beam light goes though two handlebar switches. Power for the right goes through a relay and then direct to the bult.

There is an obvious difference in the right and left high beam headlight brightness on my bike.

By standing at the front of the bike with the headlights on high beam, and looking down at the reflectors from above, the filiment reflection on the right high beam is bright white and the left high beam filiment reflection is more of a gold color than bright white.

This is not staring into the highly intense beam itself, but looking from above the beam down onto the reflections in the reflector extension of the high beam lights.

I would appreciate hearing from several riders of 02 and later Wings as to whether they can detect sub-standard brightness in the left (clutch side) High Beam headlight.

I measured mine and the right was 55 watts but the Left was only 38 Watts.

Any comments will be welcome.
 

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I might be all wet here but I'd try pulling the bike up to a wall and covering one light, then the other and guaging the brightness. I have an '02 and though one was brighter than the other until I did that. Turned out on mine, same amount of light on the wall, just one was aimed a little lower. Yours might be different.

BTW, I left the aim alone. At night I have plenty of light from the stock setup.
 

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I've noticed a difference when looking in the rear view at a bike following. I attributed it to a difference in the aim of the lights. At times it almost looks like one light was out.
 

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My 02 looked like one light was much dimmer than the other... until I adjusted it..

Wonder why Honda does not set the headlights properly at the factory ??

cosmic
 

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How did you do the measurement, determining the two different wattages?

Just curious.

Thanks
 

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Interesting.. I just figured they weren't in alignment..
 

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cosmic_chariot said:
My 02 looked like one light was much dimmer than the other... until I adjusted it..

Wonder why Honda does not set the headlights properly at the factory ??

cosmic
I thought it was on purpose to illuminate a larger area. I'd say they are adjusted properly.
 

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Discussion Starter #9
There is a difference in alignment and emitted light. The hotter the filiment, the whiter the light and that is why I asked riders to look not at the beam but at the reflection of the filiment off axis in the reflectors. If they are the same color of white, then they will likely be at the same filiment temperature.

The reason I re aimed the lights was that the whole front of the bike, from the headrace forward, was replaced after the deer strike. That is when I noticed that the left headlight was more yellow than white and paid $115 to have new high beams put in. Then there was no difference in the lower luminisity left high beam.

It was difficult to measure the voltage at the headlights, but my more agile son and I did that. Here were the readings.
Left positive 11.86 volts
Left Negative 0.29 volts
Right positive 14.000 volts
Right negative 0.24 volts.

The voltage impressed on the right bulb was therefore 13.76 volts and on the left was 11.63 volts.

If we assume that 13.76 volts will get you the rated 55 watts, and if watts is equal to voltage squared divided by the resistance, then it follows that the hot resistance of the bulb is 3.443 ohms.

Though not exact because the cooler filiment will have lower resistance, if we assume that the left bulb also has 3.443 ohms resistance, then the wattage for the 11.63 volts will be 39.29 watts.

Also, since we have a voltage drop somewhere of 2.37 volts, and with current equal to the wattage divided by the voltage, there is 3.378 amps flowing and with the demon drop wattage also being the current times the voltage, we have 8.01 watts of heat somewhere that it should not be. A 10 watt soldering iron will melt solder at 600 degrees.

Since I still have an 01 shop manual that showed both High Beams in parallel, I was convinced that there was a bad splice, untill Fred Harmon researched the circuit of the 02 and later bikes.

When I was in for service yesterday, I looked at a late shop manual (with heated seats) to verify what Fred found in the left headlight circuit and sure enough the left headlight gets its power through the start switch and the high/low beam switch, and not through any relay at all. A bummer of a circuit as far as I am concerned. The dealer still refused to beleive that is how it is wired even after I showed them in the manual.

The next time I am in the front end of the bike, I will put in a second relay and directly operate the left headlignt so it is exactly like th e right. It is rediculous to run power through the handlebar wiring and swithches. That is 1960 technology.

I would appreciate anyone taking the time to notice the color of the filiments of ther high beam light. I do all of this with the engine running so as to have regulated voltage.

By the way, Fred has on his wonderful site some photos of different bulbs and the color is obviously more yellow on the lower brightness light.

http://www.pbase.com/fredharmon/headlamps

The only thing I would add to Fred's comments is to reinforce that you must not touch the quartz envelope of the new bulb after it is cleaned with alcohol, as the oils in your skin will change the crystaline structure of the bulb and destroy its ability to pass light.
 

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I am thinking outside the box, for fun and pleasure.

Pregnant thought, I wonder if Honda wants the bulbs to be at 55W and 39W respectively for some other reason than wire routing convenience (cost more to route to both bulbs from relay), maximum switch ratings (switch can not handle both) or redundant equipment safety (relay for one, switch for other) concerns or mere poor engineering/laziness?

That 16W less power while lights are on could extend battery life to meet government regulations (Ralph Nader introduced legislation in the 70's that required the battery to start a vehicle within certain timeframes for door-open and ignition-on situations). That 16W less power could reduce Alternator or Engine heating to help mitigate the overheating issue? 16Watts less power consumed in this world, could they be complying with some Kyoto-Accord green-induced fuzzy-wuzzy? Could 16Watts less power consumed have caused the frame cracking because of the extra weight of the relay?

Ok, I have had my paranoid delusional fun, I'm going back on my medication now.

What gets me is that the bulbs fail at almost exactly the same time (24000 miles average I believe) even despite the differences you have noticed in their power consumption.
 

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Discussion Starter #11
salyzyn
Actually the bulbs that fail early are the low beams that are on 100% of the engine on time.

The only excuse to do this is reduncy but there is always the low beams that are on even if both high beams would go out as would be the case in the 01 if the fuse blew or relay failed.

A case could be made that the relay was not good for the 8 amps of load on the 01 where both high beams run from the same relay, but the low beams are the same wattage and do run from one relay. They also both run at 55 watts and all the time where the high beams are used a small portion of the time.

This one defies logic. It is easy to fix schematically, but difficult to access to accomplish the fix.

May be some country that requires seperte circuits on one of the headlight systems. It is simply a very bad deal, technologically.
 

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Tom Finch said:
The reason I re aimed the lights was that the whole front of the bike, from the headrace forward, was replaced after the deer strike. That is when I noticed that the left headlight was more yellow than white and paid $115 to have new high beams put in. Then there was no difference in the lower luminisity left high beam..
$115 ? i know the hi beams are more trouble than the low beams but what is the hourly rate at that shop ? hopefully u at least saved the old bulbs

i thought maybe u were imagining things but was curious so went out and started the bike just to check and sure enough the left hi beam is dimmer than the right, i never would have noticed it otherwise

both low beams look the same looking from the top down, lots of folks notice a difference in the low beams but thats looking from the front and is caused by the aim of the lite
 

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You guys are gettin way too deep..

Real simple.....

Take a screwdriver and adjust the left low beam up a little and then they will be even... Takes about 30 seconds

That was one of the first things I did when the bike was new...

I think Honda does that for better ilumination of the road...
 

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Discussion Starter #14
Tony,


The right - left aiming is done with a #2 Phillips near the center of the fairing. The up and down aiming is meant to be done with a hex socket, about 12 mm. However, with gloves on, the right angle drive driven gear can be turned with a gloved hand, and that is easier and faster than trying to keep asocket on the hex drive gear shaft of the up/down adjustment.

Put the bike on the stand, take a horizontal reference at the top pof the low beam and block off one then another and adjust the lower beam upward untill it is even with the higher of the two low beam positions.
 

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Tom, Since you have noted that you have a low voltage condition on the left side and the color is also different, obviously you do not have an adjustment problem as others are suggesting. Yes, they are right that Honda does align the left bulb lower than the right, just like on cars, but that isn't the problem here.

If you really look at the schematic closely you will notice two things.

First, the lamps themselves are marked as 12v 55 watt on the wiring diagram. That tells you right there that you have a problem in your specific bike since your measurement on the left lamp is lower.

Second, at a quick glance I felt that there was an obvious mistake in the wiring diagram. The lights shouldn't work the way the manual shows. They show the left lamp going directly to the Hi Beam switch which would be a major design flaw. For one, it is doubtful that switch is capable of directly handling anywhere near that much current. Secondly, if it were wired without a relay, only one of your lights would go out when you hit the starter. Since we know they both go out, it was obvious to me that it is not wired the way the manual says.

I may have to alter that thinking though. The troubleshooting guide gives a relay as a possible cause for the right lamp out, but does not give the same suggestion for the left lamp. For some odd reason it appears that the idiots at Honda really did wire only one of the high beams to a relay.

What fooled me is that the relay is cut out indirectly when the starter button is pushed. It removes voltage from the dimmer switch, which in turn cuts off the relay and the left high beam.

I think the answer to your problem is simple. You either have a bad dimmer switch or starter switch. The resistive switch will not affect the right lamp until it completely fails because 11.5 volts is still enough to turn on the relay and supply the full 13.5 volts.
 

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I wonder if this is a Feature (as opposed to a bug). It would make sense to tone down the left high beam, or turn up the right, to better illuminate the side of the road while not blinding on-coming traffic (should you forget to switch off your hi-beams).

Hey Tom... Am I gonna have my trailer before Christmas?
 

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Discussion Starter #17
Hi, Larry!

Both high beam bulbs are brand new 55 watt bulbs. I was illustrating that the left bulb is only runnning at 39 watts because of the lower voltage impressed on it.

You have come to the same conclusion that I have. Honda has done a stupid thing in this lash up. There must be a lawyer some where that caused this. No other reasonn is plausable.

It would be easy to offhand assume that one of fthe two swtiches is bad. However, there are several feet of extra wire in the right circuit and also some extra connectors.

That is the reason I pleaded for some of the riders to make an actual observation of their filiment color. If there was all of the voltage drop in one device, it would be hot enouth to destroy it. It is about 8 watts which if concentrated at a switch contact would fry it.

If Honda added that extra several feet of wire and kept the gage the same, they could easily have added enough resistance to be the culprit.

By the way, there was a change to this wiring in the 02 models and it has been shown since that time in the newer wiring diagrams.

It will be easy enough to run a low resistance (12 gage) wire from the battery through a fuse to the front of the bike and there put one of our 30 amp relays we use in the trailer, to operate the high beam lights. I am also not so fond of the quarter volt drop in the negative side wiring either. I want all the power I can get to the High beam Lights. I may run 12 gage negative service up there also.

Thanks for your comments.
 

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Discussion Starter #18
Howdy, Tom!

It would not be likely that Honda would intentionally run lower power in the light because it makes it yellow and the illumination goes down rapidly with lower temperature of the filiment. A smaller filliment that is at 4000 degrees or so will put out better light that a larger filiment at cooler temperature.

I see your trailer in line, but Christmas is very ifffy.

Relative to Christmas, I hope you and yours have a very good one. An Iraq vet is to stop by and look at the Tailwind he ordered from Iraq during his Christmas break.
 

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Although I was fairly certain that my lights were equal, I went out and checked. I could not see any discernable difference. I then got out my meter and checked the voltage to the lamps. With the engine running, I measured 13.80 volts on the right, and 13.65v on the left. For all intents and purposes, at least on my bike, the lamps are virtually identical.

In spite of some of the goofy wiring they have on this bike, I don't believe that even Honda would install wiring that is so badly underrated that you would get the kind of voltage drop you are experiencing just from line loss.
 

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Discussion Starter #20
Larry, how were you able to reach the high beam lamp wiring so easily? Also was this across the lamp or from a common ground?

It was a bear to reach the High beam bulbs on my bike, particularly the left side. Low beams is not so hard.

Thanks for taking the time to do this.

Tom
 
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