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Discussion Starter #1
I have yet to find anyone who's actually replaced their H3 and H7 with a set of LED's. If anyone's done it, how did the project go, is there enough room for the heatsink (braided cable or fan), and what are the results? Best of all, are there any photos of the headlight assembly after the conversion?
 

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Discussion Starter #2
I think replacing the H7 low beam is basically plug and play. The H3 high beam uses a socket assembly that is more than "cram the H3 in the reflector and button up". Or...?
 

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There's a lot of talk about leds at the moment. The underside of the cockpit on a KRS collects a lot of damp and condensation evidenced by the surface corrosion on the instrument housing at the back. I just wonder how long those tiny micro fans will last, or can you get an led lamp with a decent passive heatsink that will fit in the space? The advantage of HID is the relatively bulky parts can be located away from the headlight unit. LED has advantages but I'm just not sure about their cooling and whether that defines reduced reliability.



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Discussion Starter #4
This is exactly what I want to know! To date, I haven't found anyone who put LED's in their KRS.
 

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Discussion Starter #5
Party over - the H3 LED won't mount in the headlight. I got my hands on the H3 high beam socket and... nope, no way to get the heatsink through the socket assembly.

On to Plan B, finding the brightest practical (don't want to melt the bike) halogen light. The stock wattage is 55W. I have an HID in there but a) I'm not happy with the slow ignition time and b) it's somewhat(!) faked to get it in. The ignition time can be shortened by buying a new HID system (ballast, etc.). The fudged socket - not so much. Time to give it up and go back to an incandescent lamp. :(

What's the best option here? The wiring has already been boosted with relays and heavier wiring.
 

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I'm very interested in this topic. I just bought a 03 K1200gt and the light output is horrible! I live in the pnw and the winters here are dark and rainy and eat up the light of most headlights. Driving home from the dealer tonight it was really tough. I just converted a 99 Subaru Outback to LED's. The Low beams were phenomenal! But the high beams split out and can barely be seen. You don't really need the high beams to be honest.. After researching it appears you need to retrofit the special focosed beam assemblies in order for that type of bulb to work in there..

The LEDs do take up a great deal of room unlike the HIDs that you can mount the ballast remotely. I saw in the factory manual there was a HID option for the Highbeam. I've never seen a H3 used as a high beam before.. I'm thinking of going with Hids, but I don't like the warm up time.. I had a pair of HID spot beams on a bike and they took a while to get to full brightness. Not great when you have to kick them on and off when cars keep coming at you..

I've got a while before I can start wrenching on the bike.. other projects and customers are in line ahead of it..
 

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Discussion Starter #7
I saw in the factory manual there was a HID option for the Highbeam.
Is that for the Subaru or KRS? AFAIK the KRS factory manual makes no mention anything but halogen lamps.

I can't remember where, but I ran into a thread where someone made baffles to redirect light from an LED. Obviously that's not a choice with an HID. In fact, I think getting an HID in the right spot to get the optics of the headlight (reflector, baffle, lens) right is pretty much slim to none. Having had to seriously modify the high beam socket to make an HID, I'm almost certain the light-emitting spot in the lamp is most likely anywhere except were is should be.So, bottom line, the trick is to find the brightest halogen light possible. The loose end here is whether the extra heat will cause problems with the reflector or rest of the headlight. I simply don't know the answer.

Two points about wiring. The original ground wire (brown) from the headlight is under-sized and the connections are poorly made. It won't matter how good the wiring to the light is if the ground isn't to the at least the same spec, and actually should be up a point in size from the supply lines. The existing ground point should be a direct chassis ground. Keep the wire short. clean the mounting point fully, and smear di-electric grease (get it from the usual car part stores), and then make a tight connection. The grease will seal the connection and will be pressed out of the actual contact point.

A 55W lamp pulls a touch over 5A (55 watts divided by 12.4 volts - Ohm's Law). A 100W lamp approximately doubles that. The high/low switch isn't intended to carry that load. The existing wiring isn't designed to carry that load. The fix is to install a relay, controlled by existing wiring, controlling new, heavier wiring for the headlight. (there are plenty threads about the details).

Although an LED lamp, replacing the low beam H7, improving the wiring won't hurt; it'll remove what small amount of voltage drop exists (lamp current times circuit resistance equals the voltage lost - Ohm's Law again). For the LED, that drop won't be a major problem, but, since the high beam wiring must be improved, might as well do the low beam, too. If a halogen H7 has to go back in, it'll benefit from the new wiring. But about the high beam, now drawing 10A. Going back to Ohm's Law, double the current and that doubles the voltage loss. And voltage loss means a dimmer headlight.

OK, I hope everyone paid attention, tommorow there'll be a quiz on this. :D
 

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I'm paying attention! I'm still with HID as the best option for low beam which stays on all the time. Slower startup is an issue with the high beam if you like using the flasher a lot, but time from ignition to good brightness of 2-3 seconds is good enough for me and I've stopped flashing. Some that complain about poor stock lights on the K's haven't uprated their headlamp wiring for thicker or discovered the headlight height adjuster is set too low!

If you are up for more frequent lamp changes you can still go with tungsten and the Silverstar type over run lamp route. I've been experimenting with the P21 turn signal lamps to get mine brighter. Using a cheap small electronic voltage booster I am running my turn signal bulbs at 16.5 volts. The small switcher modules I'm using are only good up to 4 amps, but you can get bigger. The commercial higher brightness reduced life bulbs use a shorter filament to over run them at 14.3 volts. My experiments show with one of these switcher modules you can carry on using cheap H bulbs to get higher brightness cheaper but still sacrifice life. At least you can preset your over run lamp voltage to make your own tradeoff, there is no startup lag and you can use your flasher.

Over running a 35 watt tungsten to 55 watts will give a much brighter light than a 55W lamp but you will get shorter bulb life. I've been playing with the really cheap modules and by adding few extra components you can produce a 'soft start'. On an over run bulb you should get longer life than using the plug and play commercial bulbs.



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Discussion Starter #9
OK, my bike's still apart but the answer is clear. High wattage halogens low beam halogens aren't a good idea. The reflector is plastic and the H7 lamp rests directly on a plastic ridge or shelf. The H3 high beam sits on a somewhat complicated plastic casting in a metal carrier. I don't know how much heat the plastics will take, but once it starts to deform, life will not be fun. Halogens are, of course, plug & play relative to the original 55W lamps. LED's will require serious modification to the dust cover for almost any lamp - fan assemblies may collide with the framework behind the low beam LED. A high beam H3 LED probably will not have clearance issues, although, again, the dust cover will require major alterations. Keep in mind that both high and low beam have positive mechanical fasteners which must be closed before replacing the dust cover. That means whatever hols are drilled or enlarged in the cover must be large enough to pass the diameter of the fan and fins. The temptation is to omit the cover. Don't. Bottom line: HID's and 55W halogens are about the only realistic choices.

Now to go back out into the cold garage and button this bad boy up. With the HID's already in it.
 

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I would reach the same conlusion. 35 watt HIDs give plenty of light and less heat than halogens. But if anybody wants to keep the halogens they should re-wire the stock wiring with thicker wire and preferably right back to the battery. The thing about automotive bulbs is their wattage is always quoted at 12 volts but they are designed to run with alternator charging at about 14.3 volts. That makes your 55 watt bulb more like 65 watts. A 35 watt HID on the other hand with electronic stabilized voltage should always run at 35 watts. As for leds, it depends how sophistocated their driver circuit is. Ideally the leds should be constant current = constant brightness independent of voltage = constant wattage. However the control circuitry could be delivering higher current at 12 volts than at 14.3.



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Discussion Starter #11
Rewiring. Agreed that heavier wire is a very good idea. But... and here I must plead guilty to listening to theory over fact... easier said than done. The problem come from how the lights are tied to the bike's wiring. I stayed with assuming the common headlight arrangement: pigtail with bulb connector. At least on my bike, it's not that way at all. There is a three pin connector that goes into the side of the main dust cover (vs the removable cover for changing bulbs). Short of completely re-engineering that, the wiring inside the lamp, and the wiring coming into the lamp, going to heavier wire only goes so far before returning to the thin wire present in the OEM installation. All of that said, without rebuilding everything in sight, the only options are 55W halogens (stock) and HID's. I'm guessing but I assume a 55W HID would present no more heat load than a 55W halogen bulb. OTOH, the light output from a 55W HID is appreciably more than from a 55W halogen - handle with care.

Summing up: Re: wiring, I was wrong about that. I apologize for speaking with less than all the (obvious) facts. Re: bulb options: 55W halogen or HID for at least the H7. The same holds for the H3, although some LED's might be made to fit with drastic changes to the dust cover. I suggest taking a "you go ahead if you want, we'll watch with interest" attitude to the issue. Re: halogen bulbs: 55W bulbs are the starting point. In my opinion, they are inadequate for riding at anything beyond conservative speeds. Changing to a brighter bulb is a reasonable choice if the reflector wasn't made with silver-coated plastic. It is and that makes use of higher wattage (and hotter) bulbs problematic. Finally, claims of brighter light from the same wattage are, in my opinion, mostly marketing hype. I tried Silverstars in cars and was hard-pressed to see a noticeable difference. Not recommended.

Once again, I'll plead guilty to examining my lower bowel with my own eyes on much of what I said earlier about wiring the K1200RS/GT headlight assembly. The only saving point is Ohm's Law supports my statement about heavier wire being better for higher currents.
 

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I haven't been on this site in a while and just saw your posting.

I got tired of the dim lights on my K1200RS and bypassed the stock, thin wires with much heavier gauge wires and relays. These provide full alternator voltage to the bike instead of dropping it ~ 1 volts like the stock wires do. The increase in brightness is quite noticeable.

You can see a writeup on it here:

Make your headlight brighter

I have tried a few LED units and nothing fits very well on the low beam and not at all of the weird high beam mount.
 
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