Burned Headlight Ground - K-Bikes.com - Excellence in Motion
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post #1 of 21 (permalink) Old Dec 4th, 2005, 11:50 am Thread Starter
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Join Date: Jan 2005
Location: Spokane, WA, USA
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Burned Headlight Ground

Hi All,
Greetings from wintery Pittsburgh.
I've been mostly lurking for a while - now I have an electrical question:
I decided to give my 04K12RS a workout in cold (27F) but sunny weather and dry roads yesterday to charge the battery and keep the juices flowing (- the bike's and mine ) and discovered during the ride I had no headlight. Both low and high beams were out, and the blue hi-beam indicator light was on regardless of switch position.
I checked the fuses - both OK. Next I removed the headlight assembly and checked power at the plug with a test bulb - both headlight and high beam had full battery power against ground.
After a little more work with the Ohmmeter and a flashlight, I discovered that the ground lead from the plug receptacle to the ground strip that holds the hi-beam bulb socket was corroded and burned at the connector with said ground strip. The wire insulation was burned off for about 1/2 inch behind the connector. The white plastic lamp housing shows brown spots indicating something burned.
I cut the end of the burned wire and spliced in a new piece of wire with a new connector. Problem fixed.
Now my question:
I am running a Kisan PathBlazer Headlight Modulator that modulates the hi-beam (gets a lot of attention from cagers, I love it). Other than my older R850R, on my KRS, the low beam is always on so as I ride with the hi-beam on modulator, both lights are on continuously. Could this be the reason the ground wire was overloaded? Anyone with similar experience? Perhaps the designer-gods in the Vaterland had not designed this bike for riders that keep the hi-beam on at all times? Any suggestion for fixes (such as adding a separate ground wire for the headlight)?

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post #2 of 21 (permalink) Old Dec 4th, 2005, 1:18 pm
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See Archives

Jurgen, do a search of the archives, this problem has come up before, I don't remember root cause or the fix for sure but I know you will find good information in the older posts.
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post #3 of 21 (permalink) Old Dec 4th, 2005, 1:53 pm
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I have no personal experience on this with the KRS/GT, but, as stated, there are many posts confirming the corrosion due to water and melting due to higher wattage bulbs being used.

As far the modulator, I doubt that it provides too much of a load and is the cause. Also, many riders do ride with their high beams on all of the time during the day to make themselves more visible, so, that shouldn't be the problem.

My thoughts are that the corrosion occured first. A corroded ground can cause increased impedance which will then cause increased current draw. If the corrosion was too bad, the circuit would simply see an "open", however, if it was making a marginal connection, arcing could occur and cause the melt down.

I am considering changing to HID bulbs. These draw less current when running, but, their start ballast requires a dedicated line run to the battery if you are going to do it right. I will probably rewire BOTH the headlight and the horn grounding wires while I am in there since these seem to be poorly designed.

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post #4 of 21 (permalink) Old Dec 4th, 2005, 2:01 pm
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Location: Bristol, VT, USA
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Originally Posted by jurgen
Any suggestion for fixes (such as adding a separate ground wire for the headlight)?
Get it replaced under warranty!
They did mine.

02 K12RS (Molested)
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post #5 of 21 (permalink) Old Dec 4th, 2005, 3:35 pm
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I recently had my headlight replaced under warranty as the adjustor was broken. While I had it out I took the time to wire in relays and a ground direct to the battery with 12 ga. wire. I swear the Philips vision plus bulbs are putting out more ligh t now, but perhaps I was too used to the out of adjustment lighting pattern....
Traditionally, BMW uses marginally acceptable wire gauges throught the system.
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post #6 of 21 (permalink) Old Dec 4th, 2005, 4:51 pm
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About the marginal wires, all manufacturers use the minimum size wire they can get away with. I have checked the voltage at headlights on many makes and models of cars and motorcycles and found them all wanting. The best way is to use the original headlamp wiring to control relays wired direct to the battery. New heavier ground wires as well.
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post #7 of 21 (permalink) Old Dec 5th, 2005, 4:14 am
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HGP3, That's what I've done. Although lower voltage at the lamp holders has its upside - much longer bulb life. When you put on lamps like indicators, brakes or main, and see any dimming, it's a sure sign of voltage drop due to skimpy wire.

Shared ground wires are the biggest culprits so a second parallel wire to the battery negative can be added, if you don't want to go the full relay route. Not sure if K's have bulb failure monitoring to its brain, some monitoring units must route the grounds via a resistor in the unit and they can't be shunted.

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post #8 of 21 (permalink) Old Dec 5th, 2005, 10:22 pm Thread Starter
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Location: Spokane, WA, USA
Posts: 14
Thanks All for the advice - I'll talk to my friendly dealer to see about warranty. BTW, so far I'm using the stock lightbulbs, no higher wattage. I'm thinking of adding a set of PIAA lights in the spring, though.

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post #9 of 21 (permalink) Old Oct 8th, 2006, 8:05 pm
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Location: Montgomery Village, MD, USA
Posts: 76
dealer won't listen

So I have read all the other threads on this topic. My 2003 K12RS is definately suffering from a bad headlight ground. However, I take the bike to dealer for my scheduled appointment to fix this problem and the problem fixes itself. I leave the bike at the dealer and explain/describe and insist. The bike is still on warranty. They can't make the lights fail. They have the bike for a week. When they call saying my bike is ready to be picked up I explain its a common problem and that they should go back and look at the headlight ground. They don't want to do that. So I take the bike home, ride it for a week without any headlight problems. This morning the headlight fails when I start the bike after sitting for a few days (the bike, not me). The high beam indicator is on and I have no low or high beam. I ride the bike for about 5 miles and the headlight comes back. Damn this is frustrating. So, do I keep riding it until the headlight fails completely or find another dealer? There is another one in the area but getting an appointment will take weeks. Or perhaps tackle the fix myself?

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post #10 of 21 (permalink) Old Oct 9th, 2006, 8:59 am
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I own a 98' K12RS which had the same problem as Bushman explains. Its easy to say if its the burnt ground wire. Open your headlight rear cover and if you smell something burnt, its your ground wire inside the headlight assembly. Another way to check it is to jump the ground wire, connect the parking light (if its working) ground connection to groung spring which holds the hi-beam bulb. That will tell you if the burn is inside the headlight assembly. Hope this helps.

Is this a common occurance because we start the engine with hi-beam "on" or do somebody here take extra step to turn it off before start and then turn it back on when on the road.

I learn a great deal reading all your posts. Cheers

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