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TECHNICAL MOTOBRICK WRENCHING In Remembrance of Inge K. => The Motobrick Workshop => Topic started by: foliver on March 31, 2022, 07:19:36 AM

Title: BMW k75 ( K100 ?) headlight dismantling
Post by: foliver on March 31, 2022, 07:19:36 AM
Hello all
I feel my headlight is dim, i've cleaned all contacts with deoxit, the bulb is clean, but i would like to dismantle the unit to clean the chromed interior ( i know it's fragile), how can dismantle the front lens from the chromed back part? Or is sealed for ever?

Thanks all for your advice

Fabian
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: Laitch on March 31, 2022, 10:23:52 AM
I replace my OEM 60/55 halogen bulbs every two years. It's a characteristic of halogen bulbs to slowly lose their brilliance over time. I ride forested roads and highways at night and I'm satisfied with their performance. Many riders have installed headlight relays. These devices improve OEM halogen bulb brilliance and also preserve headlight switches by lessening the wearing effect of full power running through them, although the halogen bulbs themselves still wear out at the same rate. At the cost of 10USD for two bulbs, I'm ok with the originals.

There are also a few LED bulbs that are effective substitutes for halogens that riders here have reviewed. frankenduck likely posted his recommendation here, as have others.

On my K75, once the chrome ring surrounding the glass lens is removed, six clips (#7 in the diagram) are removed to enable cleaning of the lens. If your headlamp is that style, take a photo of the clips in place before you disassmble. Your moto might have the same setup or it might have been replaced with a sealed beam, all of which would be replaced. You will soon find out.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: jad01 on March 31, 2022, 10:30:21 AM
I've had pretty good results cleaning the inside of my MC and car headlights without needing to detach the lens from the body of the light.
1. Pull the headlight off of the bike
2. Remove the lamp (bulb)
3. Pour a little 70% rubbing alcohol into the light (a couple of tablespoons or so) through the opening where the lamp fits
4. Swish it all around
5. Drain it out through the opening where the lamp fits
6. Repeat once and then leave it open to dry before reinstalling the lamp

This has always made a huge improvement on my lights. 112350
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: The Mighty Gryphon on March 31, 2022, 11:06:45 AM
I've had pretty good results cleaning the inside of my MC and car headlights without needing to detach the lens from the body of the light.
1. Pull the headlight off of the bike
2. Remove the lamp (bulb)
3. Pour a little 70% rubbing alcohol into the light (a couple of tablespoons or so) through the opening where the lamp fits
4. Swish it all around
5. Drain it out through the opening where the lamp fits
6. Repeat once and then leave it open to dry before reinstalling the lamp

This has always made a huge improvement on my lights.

+1  Whatever you do, DON'T TOUCH the reflector with anything.  You will leave microscopic scratches that will scatter the light, permanently reducing the light output.  A slosh with rubbing alcohol is the only thing gentle enough to not damage the finish of the reflector.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: foliver on March 31, 2022, 11:25:19 AM
Hi, thanks all for your replies
Confirmed it’s the sealed version..thanks Laitch for the diagram
I’ll follow Jad tip, remembering what Mighty points
I’ll change the bulb, I ‘ve never change it, so I guess after the cleaning,  the lamp change,  and socket cause I’ve an intermittent contact that appears twice), it will punch me es the sun!
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: frankenduck on March 31, 2022, 11:52:02 AM
LED vs. OEM Halogen

(http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/hltest/hltestpics666/1aL.LED.Fact.JPG)
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: Laitch on March 31, 2022, 12:07:21 PM
LED vs. OEM Halogen

(http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/hltest/hltestpics666/1aL.LED.Fact.JPG)
It seems to me that in the photo, the halogen light on the right seems to illuminate each of the door panel edges as well or better than the white light on the left; however, it could be that from individual to individual, light receptors in vision structure vary in their response to different colored light. That appearance could also be an artifact of the angle of each headlight.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: foliver on March 31, 2022, 12:19:47 PM
Are today less direct replacements for halogen ones?
What can be the consumption of led ones?
I’ve seen new halogens that claims 50% more brightness for the same wattage, true?
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: frankenduck on March 31, 2022, 01:04:13 PM
It seems to me that in the photo, the halogen light on the right seems to illuminate each of the door panel edges as well or better than the white light on the left; however, it could be that from individual to individual, light receptors in vision structure vary in their response to different colored light. That appearance could also be an artifact of the angle of each headlight.

It's more due to my camera's exposure and how the camera processes different colors and brightnesses at one exposure level. In real life you can see the lines of the rectangles on my garage door just fine for the LED beam.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: frankenduck on March 31, 2022, 01:15:12 PM
Are today less direct replacements for halogen ones?
What can be the consumption of led ones?
I’ve seen new halogens that claims 50% more brightness for the same wattage, true?

The LED H4s that I use are about 40/20W vs. the 60/55W of the factory halogen bulbs.

Yes, plug-n-play direct repalcements.
(http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/hltest/hltest3.jpg)

I've tried all sort of headlights and the LEDs are by far the best. I used to run 100/90W halogens (with relays and upgraded wiring) but have replaced all of those with LEDs now.

The first few years of H4 LEDs were pretty crappy but by 2020 they started getting much better.  The even make the crappy headlight of the K75S work pretty well.

If your headlight has the locking ring mounting then you need to be sure that the base of the LED is less than 31mm. (Many are not because of the cooling fan on H4 LEDs.)

(http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/hltest/hltest2.jpg)
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: foliver on March 31, 2022, 01:23:32 PM
Nice explanation, thanks Frankenduck
Any link or name and model you can suggest?

Thanks
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: frankenduck on March 31, 2022, 01:30:42 PM
If you want to run a H4 halogen (some countries with vehicle inspections don't allow LEDs yet) then both the Philips X-treme Vision and the OSRAM Night Breaker Plus are good.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: frankenduck on March 31, 2022, 01:35:38 PM
Nice explanation, thanks Frankenduck
Any link or name and model you can suggest?

Thanks

The ones I bought from Amazon are no longer available but if you find one that looks like my picture above it should work.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: The Mighty Gryphon on March 31, 2022, 02:15:13 PM
That photo LED vs Halogen is pretty impressive, especially the cut off on the opposing driver side.  That has been the major fault with all the LED h-4 replacements that I've seen.  Just curious, what bikes were those bulbs in?

Are there any issues with getting that LED lamp into the fairing on an RT.  One of the worst jobs I've ever had on the side of a road in the middle of New Mexico was doing a headlight bulb replacement.

Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: frankenduck on March 31, 2022, 02:38:45 PM
What bikes were they tested on? No bikes.

They were both RS/RT/LT headlights though.

Here's my high tech testing lab.  They were both run from the same fully charged battery with same length and gauge of wire in order to make it an apples to apples comparison.

(http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/hltest/hltest4.jpg)

Difficulty of replacement on RS/RT/LT bikes? About the same major PITA as usual for RS/RT/LT bikes except a tiny bit more difficult since the plastic "rim" of the LED bulb is a wee bit thicker so you have to push the ring in a little harder.  My K1100LT was a real pain.  On the bright side, since LEDs last "forever" you should only have to do it once at home and not have to deal with it while out touring.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: The Mighty Gryphon on March 31, 2022, 06:49:50 PM
Cool test rig, explains why the beam is higher on the LED side of the test photo.

Looks like LED's have finally made the big time.  Think I'll have to look for a couple.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: Laitch on March 31, 2022, 07:06:18 PM
Looks like LED's have finally made the big time.
frankenduck did the best he could with what he has and it's a baseline for further research. To me though, one bulb just emits a different color light than the other in his trial. What interests me about LEDs is their durability but what I'm seeing here doesn't convince me having one will make my life much different.

German industry has made LED bicycle lights into effect tools for road navigation and they must meet uniform codes of performance. Peter White Cycles created a comparison demonstration that was helpful for me in choosing among different products. This is how White assembled it. (https://www.peterwhitecycles.com/headlights.php)
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: frankenduck on March 31, 2022, 07:51:56 PM
frankenduck did the best he could with what he has and it's a baseline for further research. To me though, one bulb just emits a different color light than the other in his trial. What interests me about LEDs is their durability but what I'm seeing here doesn't convince me having one will make my life much different.

German industry has made LED bicycle lights into effect tools for road navigation and they must meet uniform codes of performance. Peter White Cycles created a comparison demonstration that was helpful for me in choosing among different products. This is how White assembled it. (https://www.peterwhitecycles.com/headlights.php)

You're right that one picture against a garage is just one data point but I can tell you from experience that it's more than just a different color light.

I've tried LED headlights in all three types of K bike headlights (and my cars where I initially tried LED headlights) and it's an improvement, even over the 100/90 halogens I was running.  The bike where it makes the most difference is the K75S. I don't know if you've ever ridden a K75S at night but that S headlight is just horrible. As in really, really, really BAD! My K75S bikes, now with LEDs, are much better for riding at night. I can actually see what's ahead of me and it's definitely SAFER.

If you're looking for a reason to NOT run LED H4s then technically they're still not legal as replacements for halogens and only for off-road use. That's a non-issue for me though. The early LED headlight bulbs sucked due to scatter and not really being all that bright but they're MUCH better now. Back before 2020 or so you COULD get decent LED H4s but only if you were willing to spend upwards of $80-90 each.

And if you don't want LED then it's worth it (and safer) to instead get a good halogen like one of the ones that I referenced a few posts up. When I bought my K1 (same headlight as RS/RT/LT) a previous owner had installed an Osram H4 and I could tell on my first night ride that it's a quality bulb.

JM02
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: Laitch on March 31, 2022, 09:41:28 PM
I don't know if you've ever ridden a K75S at night but that S headlight is just horrible.
If you're looking for a reason to NOT run LED H4s . . .
. . . if you don't want LED then technically they're still not legal as replacements for halogens and only for off-road use.
 
I need no reasons for not running LEDs but I'm not rejecting them, either. I've only ridden a Standard with an H4 and a Bosch circular lens. Once I aimed the light where I wanted it—I rejected the tape on the garage wall method—and oncoming traffic wasn't signaling that it was blinding, I was good to go. I'll admit it's easier to aim and correct a headlight mounted in the Standard's two-bolt headlight cowl than the fairing setup. Nevertheless, ordinary Osram or Sylvania H4 bulbs are good enough for me; however, as far as LED legality goes, I doubt a motor vehicle inspection here in VT (even as self-righteous as it is) would ever delve into the composition of the headlight bulb as long as its high/low function operated. In CA or MA, all bets are off.  :laughing4-giggles:

Auxiliary LED driving lights have an effective place in the scheme of things, for certain, providing both an increased degree of oncoming conspicuity and specific illumination of the road ahead.  112350
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: frankenduck on March 31, 2022, 10:05:42 PM
I'll admit it's easier to aim and correct a headlight mounted in the Standard's two-bolt headlight cowl than the fairing setup.

Having owned dozens of K bikes, the RS/RT/LT fairing mounted setup is MUCH easier to fine tune than the bolt on each side system used by the standard and C bikes. No tools required either.

(http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/hlh4.change/hlh4.c20.jpg)

It also has the three position white lever on the right side that allows a super simple 3 position adjustment to adjust the beam height dependent upon passenger/bag loading.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: foliver on March 31, 2022, 11:40:35 PM
Having owned dozens of K bikes, the RS/RT/LT fairing mounted setup is MUCH easier to fine tune than the bolt on each side system used by the standard and C bikes. No tools required either.

(http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/hlh4.change/hlh4.c20.jpg)

It also has the three position white lever on the right side that allows a super simple 3 position adjustment to adjust the beam height dependent upon passenger/bag loading.

That really seems more precise and fast design than my k75C bike
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: Laitch on April 01, 2022, 12:57:12 AM
. . .the RS/RT/LT fairing mounted setup is MUCH easier to fine tune than the bolt on each side system used by the standard and C bikes. No tools required either.
I'll admit that looks pretty simple all laid out there but using a hex wrench hasn't been particularly challenging either.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: milq on April 01, 2022, 12:09:58 PM
Hello all
I feel my headlight is dim, i've cleaned all contacts with deoxit, the bulb is clean, but i would like to dismantle the unit to clean the chromed interior ( i know it's fragile), how can dismantle the front lens from the chromed back part? Or is sealed for ever?

Thanks all for your advice

Fabian

Fabian, has your bike been upgraded with a relay for the headlight? If not, you might check out Frankenduck's write-up on the matter. It can also benefit the life of your headlight dimmer switch.

http://www.motobrick.com/index.php?topic=268.0
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: foliver on April 01, 2022, 12:27:24 PM
Fabian, has your bike been upgraded with a relay for the headlight? If not, you might check out Frankenduck's write-up on the matter. It can also benefit the life of your headlight dimmer switch.

http://www.motobrick.com/index.php?topic=268.0

Uuups, thanks milq! No, it’s all original.
I started to read the link yo provides, seems a good move to do.

Txs!!!

I’ve found an Osram night breaker here, so I’ll use that one to start, and anyway I’ll buy a new socket cause the one on the bike has the plastic melted around one of the pin connectors. May be is the time to add the relay on the move…
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: frankenduck on April 01, 2022, 02:46:23 PM
If you're replacing the H4 socket then get a ceramic one. I use them on my Ks. They don't melt.

(http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/hl.relays/hl.rel1.jpg)



Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: foliver on April 01, 2022, 03:44:18 PM
If you're replacing the H4 socket then get a ceramic one. I use them on my Ks. They don't melt.

(http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/hl.relays/hl.rel1.jpg)

Thanks Frankenduck, I’ve located  close to my house!
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: The Mighty Gryphon on April 01, 2022, 10:12:17 PM
If you're replacing the H4 socket then get a ceramic one. I use them on my Ks. They don't melt.

(http://www.kbikeparts.com/classickbikes.com/ckb.tech/0.ckb.tech.files/hl.relays/hl.rel1.jpg)

The plastic OEM connector will weld itself to the contacts on the H4 bulb, making it nearly impossible to remove.  Don't bother asking me how I know this, I'm not telling.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: foliver on April 01, 2022, 10:45:43 PM
The plastic OEM connector will weld itself to the contacts on the H4 bulb, making it nearly impossible to remove.  Don't bother asking me how I know this, I'm not telling.

jajajaj, i can imagine your scenario...

Mine has lost part of the shape,it stops working after 2 days of the revival, it develops an intermitent contact.

The blue light on the Speedo stays on, i discovered that is a sigh of non working headlight..

My problem in the starter relay-battery relation ( maybe plus another electrical anomaly, ignition key? ) continues, and i've seen that if the starter keeeps running after start up, i don't have light on the speedo, and i cannot turn off the bike.

I know is another story, not for this thread, but i bring it here, cause i've discovered the intermitent contact of the headlamp, after stall the bike in 3rd gear to shut off.

2 days ago when it happens again, i thought if it was the cause of the melted socket.... ( i suppose it's not related..) but..


Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: rbm on April 02, 2022, 09:12:25 AM
A ceramic socket is not immune from melting.  Mine did because the connection corroded over time and caused excessive resistance.  The corrosion narrowed one of the wires and the heat generated melted the insulation.  My advice - keep and eye on maintaining clean electrical connections.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: Laitch on April 02, 2022, 09:15:23 AM
My problem in the starter relay-battery relation ( maybe plus another electrical anomaly, ignition key? ) continues, and i've seen that if the starter keeeps running after start up, i don't have light on the speedo, and i cannot turn off the bike.
There are a few possible causes, two of which are considered in my response to this query (http://www.motobrick.com/index.php?topic=14738.msg131540#msg131540).

To stop starter run-on if it happens, several members here have installed battery-isolator switches (https://www.google.com/search?client=safari&rls=en&q=battery+isolator+switch&ie=UTF-8&oe=UTF-8).
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: frankenduck on April 02, 2022, 09:25:53 AM
A ceramic socket is not immune from melting.  Mine did because the connection corroded over time and caused excessive resistance.  The corrosion narrowed one of the wires and the heat generated melted the insulation.  My advice - keep and eye on maintaining clean electrical connections.

What actually melted?

a) the ceramic
b) the plastic cover for the socket
c) the wire insulation

Ceramics don't melt until very high temps.

How old was it? Do you live near salt water?

With new socket terminals and a new H4 bulb it should take a long, long time for corrosion to build up.

I've been using ceramic H4 sockets in my Ks since 2013 and never had any issues.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: foliver on April 02, 2022, 09:35:24 AM
There are a few possible causes, two of which are considered in my response to this query (http://www.motobrick.com/index.php?topic=14738.msg131540#msg131540).

To stop starter run-on if it happens, several members here have installed battery-isolator switches (https://www.google.com/search?client=safari&rls=en&q=battery+isolator+switch&ie=UTF-8&oe=UTF-8).

Hi Laitch.
This problem is my main problem now, and the isolator switch is a must have for me now. I'll install one for sure.
I'm reading re reading he link you give me, my green button seems ok under the finger, but may be it needs a good cleaning anyway.

The starter switch ( the one with the key, i mean) yesterday behaves strange at the top position, i'm in the obligation to clean it, in fact, i've cleaned an old one that the previous owner replace it and keeps, and the switch part is clean now, may be i can switch to this one to test if the problem persist.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: foliver on April 02, 2022, 09:39:38 AM
What actually melted?

a) the ceramic
b) the plastic cover for the socket
c) the wire insulation

Ceramics don't melt until very high temps.

How old was it? Do you live near salt water?

With new socket terminals and a new H4 bulb it should take a long, long time for corrosion to build up.

I've been using ceramic H4 sockets in my Ks since 2013 and never had any issues.

Hi Frankenduck.

the area around of one of the pins in the plastick soked melted, i don't know when, may be time ago, i've never unmount the headlamp before so i don't know when it happens.

Wires are fine.

https://articulo.mercadolibre.com.uy/MLU-455372626-fichas-socket-conectoras-p-lamparas-h4-ceramica-x-par-f122-_JM

this ones are the sockets i'll buy to replece them, i'll solder the new wires to the older one, and cover the joint with thermocontactil tube.


Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: Laitch on April 02, 2022, 09:50:18 AM
Hi Laitch.
This problem is my main problem now, and the isolator switch is a must have for me now. I'll install one for sure.
I'm reading re reading he link you give me, my green button seems ok under the finger, but may be it needs a good cleaning anyway.
The link I gave you also mention the starter relay and that should be investigated to determine it its contacts are fused. Have you done that?
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: jad01 on April 02, 2022, 09:52:06 AM
It seems to me that in the photo, the halogen light on the right seems to illuminate each of the door panel edges as well or better than the white light on the left; however, it could be that from individual to individual, light receptors in vision structure vary in their response to different colored light. That appearance could also be an artifact of the angle of each headlight.

Yeah, the color of LED light has been an issue for me as well.  I love the technology, but the the 3500K light provides much better contrast on the road for my eyes than the super white 6500K that seem to be predominant currently.  I had 7' truck lights in one of my Miatas for awhile and just didn't see as well as with halogens.  I keep my eyes open  :laughing4-giggles: for 3500K H4 in in a reputable brand, but have seen any so far.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: The Mighty Gryphon on April 02, 2022, 09:52:29 AM
Rob, I don't think it was corrosion that caused my problem.  I clean the contacts with Deoxit when I replace headlight bulbs every 3 years or so.  The contacts are always nice and clean.  Chalk that up to my OCD maintenance habits.

I suspect the problem is lack of cooling.  First, the fairing and the rubber boot on the bulb limit cooling airflow on the rear of the bulb.  Second, I have an Eastern Beaver relay harness that puts full power on the bulb, and third, I have been known to ride long distances in hot desert temperatures(120F/48C).

Even when the connector melted, the wires only had their insulation melted for a centimeter or so from the connector that had turned into a plastic blob.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: jad01 on April 02, 2022, 09:53:42 AM
Fabian, has your bike been upgraded with a relay for the headlight? If not, you might check out Frankenduck's write-up on the matter. It can also benefit the life of your headlight dimmer switch.

http://www.motobrick.com/index.php?topic=268.0

Lots of good info in here!  112350
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: The Mighty Gryphon on April 02, 2022, 10:03:58 AM
Yeah, the color of LED light has been an issue for me as well.  I love the technology, but the the 3500K light provides much better contrast on the road for my eyes than the super white 6500K that seem to be predominant currently.  I had 7' truck lights in one of my Miatas for awhile and just didn't see as well as with halogens.  I keep my eyes open  :laughing4-giggles: for 3500K H4 in in a reputable brand, but have seen any so far.

That has been my experience as well.  I have LED spotlight driving lights on my bikes, and despite the fact that they are supposed to put out more light than my headlight, for some reason they have a bit less ability to illuminate as far down the road as the halogen H4. 

I can't say why.  Is it scatter or lack of sensitivity of my eyes at the wavelength?  They are incredibly bright to look at, even from a long distance, but at night they have little ability to reach out to long distances.  I noticed that in the link Laitch posted, the author mentions older eyes having less sensitivity to some wavelengths.

Another problem I have noticed is that LED's illuminate road signs much more than the headlight.  Again, I don't know if this is a symptom of poor beam control of the light lens or the wavelength of the light, but the glare from the signs blinds me to the deer lurking on the roadside just beyond them.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: foliver on April 02, 2022, 11:58:57 AM
The link I gave you also mention the starter relay and that should be investigated to determine it its contacts are fused. Have you done that?

Hi Laitch, the starter relay is new ( 4 weeks), when i first try to start the bike with the new battery, the starter keeps running, so the relay stays connected, with a screwdriver i tap on it and it releases.
After charging again the batterie all went normal, but the problem repeats time to time....the bike always starts now, but sometimes the bike don't want turn off until i stalling it....and the relay opens again...
Do ou think i need to open it and sand the contacts?

when i boost the battery with external charger and it reach 12,9-13, the bike starts like a fire spark, fast.
All the earth points was cleaned and deoxit.


Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: rbm on April 02, 2022, 02:22:55 PM
What actually melted?

a) the ceramic
b) the plastic cover for the socket
c) the wire insulation

Ceramics don't melt until very high temps.

How old was it? Do you live near salt water?

With new socket terminals and a new H4 bulb it should take a long, long time for corrosion to build up.

I've been using ceramic H4 sockets in my Ks since 2013 and never had any issues.
The copper wire melted through right at the connector like a fuse, the insulation near the connector also melted and the ceramic was blackened.  The plastic surrounding the socket also melted.

The dip beam lead was what failed.  I don't know the cause of the corrosion but the uint was not so old, maybe 5-6 years and I don't live anywhere near saltwater.   I suspect that some of the strands in the wire might have been physically damaged and it degraded over time.   It happened on a day trip and I had to drive home with no headlight at night.  Scary experience since I know I was totally invisible to drivers.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: daveson on April 02, 2022, 05:27:04 PM
Strange that the relay will unstick when you stall it. When you stall it that will pump up the Amps. Maybe that's why it unsticks,  from the heat of the higher Amps. My brick read 100 Amps once with a stall test (when I installed a circuit breaker)

You don't want to keep pumping that heat through your wires. You want a proper isolator switch. In the mean time you can go the quick, cheap lazy way I did. You can probably get the switch at your local hardware store. Disconnect the battery earth cable from the gearbox. Bolt the isolator switch to the gearbox. Then bolt the earth cable to the isolator switch. In half an hour you can do it and still have time for a smoke.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: Laitch on April 02, 2022, 07:18:37 PM
. . . when i boost the battery with external charger and it reach 12,9-13, the bike starts like a fire spark, fast.
All the earth points was cleaned and deoxit.
Have the battery load-tested soon and let us know the results. It doesn't seem like it has enough charge, regardless of how new it is.
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: foliver on April 02, 2022, 10:48:13 PM
Thanks Daveson and Laitch, i just started with what i have at home. Saturday afternoon...
So i dismantle the starter relay, and i polishit with 350 sand paper, here some before after pictures.
I've switch to another the starter ignition ( the main key switch).

Monday i'll grab an isolator switch, and after finishing my job test the battery

txs!!!!
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: frankenduck on March 15, 2023, 02:40:29 PM
The LED H4s that I use are about 40/20W vs. the 60/55W of the factory halogen bulbs.

Just to update this:

Out of curiosity I decided to measure the actual currents for the H4 LED high and low beams. Attached to a battery at 12.67V both the high and low beams draw 2.12 amps so each beam is only consuming 27W vs. the 60/55W of a non-LED H4. Therefore, about half as much current is flowing through the contacts in the left combo switch. The LED H4 not only puts out a better, brighter beam with accurate beam patterns but it is also easier on the high/low beam contacts in the left combo switch. It's a win-win. Better lighting and less switch wear. 112350
Title: Re: BMW k75 ( K100 ?) headlight dismantling
Post by: foliver on March 15, 2023, 03:34:11 PM
Very nice info Frankenduck