Led Electrical Mystery?

[madmax]

Hi every one, I have a strange electrical mystery while I was changing my rear stop/tail lights to LED’s. My bike has 4 bulbs/lamps at the rear . Two in the trunk & two below the licence plate at the bottom.
All these Led bulbs are P21/5W - Led 1157- Bay15d Bulbs. A direct replacement for the standard bulbs. I’ve tested each led across a battery & all are OK.
Now this is where it gets interesting. With standard bulbs everything works OK.
If I change only the bulbs in the trunk to leds, then the leds don’t work. If I remove the lower bulbs, then the trunk leds work. If I mix any combination of leds with filament bulbs then problems. Nothing seems to work correctly. With all leds fitted, no problems. Strange!
Now all 4 bulbs are in parallel, with just 3 wires. Earth –ve. side light +ve & stop light +ve. So why does a filament bulb in parallel with a Dual led have this effect.?
I’ve also changed the indicator bulbs to leds. The front are also dual filament type. Not a problem as the side light cable is disconnected at the front on my bike. So I connected it up to see what happens. Sure enough, problems.
Indicator stayed on, when side/ running lights are on??? Fitted standard bulb everything OK.
Here in the UK you can’t have amber lights on the front of your bike ‘On’.
Amber lights should be indicators only.
Now that I’ve fitted Leds all around the bike, every thing is working fine.
So the question is why does having a filament bulb in parallel with a led cause this problem.? It may be the fact that they are dual Led bulbs.
I have tried two different makes with the same outcome.
It will be interesting to see your comments.. Just to let you know I’ve been into electronics for 50 years & I cannot figure this one out ?

[Nails]

This might not have been addressed here because few XII have the "GoldWing" fender lights. I understand that Honda sued MaKa over it, and so since an early model year XII painted over the fender lens and abandoned it. I removed that paint, inserted 1157 sockets into the housing (which is still there), and started using those lights as part of getting rid of my trunk.

I also encountered issues, complicated by not being able to find reliable sockets. I wired these from scratch, working from the elec plug that used to go to the trunk. (I added a fender taillight at the same time, so no big deal.) In other words, I couldn't figure it out either.

I'm suggesting starting over wiring these fender lights from sources under the trunk. I bet that'll be easier than trying to sort the existing harness, which obviously wasn't designed with LEDs in mind.

But I'm waiting for Dave to chime in, using his swell circuit-chaser app (that I'm very jealous of).

[triton28]

Hello Nails, madmax;
sorry Nails but my circuit chaser app is only a coloured schematic from a supplement, a ruler and pen and paper. No electronic wizardry here.
Max I am wondering if the imbalance in resistances could be a factor even though the filament and the LED are wired in parallel and in theory it shouldn't matter. Perhaps the filament is stealing all the available power, just a guess here.
The main thing is you have all systems working as they should, but that is a real puzzler of an occurrence.
Good talking with you
Dave

[VoyKimmer]

LED’s need proper continuity negative and positive wired correctly. Filament bulbs do not. I have found on mine that the rear end lights where not wired correctly from the factory. I reversed the wires and everything worked correctly. Check continuity in each socket.

[Nails]

The only thing worse than being jealous of something is being jealous of something that doesn't exist.

[madmax]

Hi, thanks for your comments, My bike didn’t have a rear fender light when I bought it. But one became available on eBay so I got it and fitted it. The wiring just connects to the spare connector behind the seat, next to the trunk connector. These are just connected together in parallel.
In theory there shouldn’t be a problem.
I’ve checked all earths to black / yellow wire & are OK. Even between lamp holders every thing is OK. I used my Fluke 87 on the connector behind the rear seat to measure the voltages. Again no problems.
If there was a reversed connection then the led wouldn’t work, but they do, so I can count that out as a problem. Like I said before if all are Leds then no problem.
So the connectors & lamp holders must be OK.
Change to filament & every thing OK, but mixing them is a no go. I have spent hours trying to figure this out. The leds I used for the indicators are a different make & style but the same problem when the other half of the Led on the front indicators are connected. ie. When the running lights are on, then problems.
I’ve checked each LED & they work OK. I’ve used a battery & a power supply to see if there was any difference. The leds work fine. +12volt to either or both connectors & - ve to the case. They work great. Strange.
I hate having a problem I can’t explain. I’ve now given up trying to figure it out.
Leds fitted & everything works OK. This is going to niggle me for ages

[Nails]

I hate having a problem I can’t explain. I’ve now given up trying to figure it out.
Leds fitted & everything works OK. This is going to niggle me for ages

Well, I do hope you get over it. I did.

Now wire in one of those flashing units -- brakes flash four times before staying on -- and you'll be welcomed right through the Pearly Gates.

[triton28]

"Now wire in one of those flashing units -- brakes flash four times before staying on -- and you'll be welcomed right through the Pearly Gates."-Nails.

I bought some of those and they definitely grab the attention of those following behind me. Pretty neat plug and play install. I have them in the top trunk and lower fender lights. I figured I needed the flashing brake lights as I have 14 separate Red tail light bulbs on the back.
I know I know, that sounds like a lot but 10 of those are the wee little T-10 bulbs in the Markland saddlebag/trunk top rails and rear mudguard light assemblies. I saw a post awhile back about installing T-10s into the unlit reflector portion of the rear turn signal housing so those got added as well. That was a simple mod using a short portion of a 3/4" barbed plastic hose connector epoxied on top of a 1/2" hole drilled into the unlit portion. Then I used a pigtail from the front marker lights and it fits snugly into the bore of the pipe connector-voila, an extra 2 rear facing T-10 bulbs.
I made a mistake when I installed my first illuminated mudflap, for some brain dead unknown reason I wired it into the saddlebag side marker harness. What a pain in the %s@ that was every time I wanted to remove the saddlebag or the rear fender portion! I had to remove the signal light and disconnect the bullet connectors. Finally I clued into my mistake and wired it into the lower fender light harness behind the lower fender tail/brake light assembly--much better.
Anyway, I gotta go and rescue some work hardened rubber carburetor ducts from a softening experiment as it is almost the 12 hour immersion time.
Later,
Dave

[GrandpaDenny]

I bought flashing LED 1157 bulbs from Amazon. What's really cool is they flash in different patterns every time I hit the brakes. Sometimes all at the same time, sometimes like wig-wags, sometimes the trunk lights wig-wag and the fender light doesn't, sometimes the other way around. Really neat.

https://smile.amazon.com/gp/product/B07 ... UTF8&psc=1

[Nails]

I bought flashing LED 1157 bulbs from Amazon.

I bought similar bulbs from SuperBrightLEDs, but they quit selling them. Thanks for the alternate source.

So I don't really have a flashing unit, just the smart flashing bulbs. I only use one (bright) taillight because the taillights in the fender quit working again. But when I hit the brakes that single taillight flashes and the fender lights fire up (also bright LEDs).

Has anyone found an aftermarket 1157 socket that actually works? It needs to be short out the back -- limited clearance in the fender housing.

[KPAX]

This might not have been addressed here because few XII have the "GoldWing" fender lights. I understand that Honda sued MaKa over it, and so since an early model year XII painted over the fender lens and abandoned it. I removed that paint, inserted 1157 sockets into the housing (which is still there), and started using those lights as part of getting rid of my trunk.

Nails, how did you remove the paint? Once removed is it a standard red lense?

[Nails]

Nails, how did you remove the paint? Once removed is it a standard red lense?

I used a wire wheel on a Dremel -- nothing complicated. It's pretty butchered on the inside. I put a couple bright red LEDs in there, and it looks fine on the bike.

What's not so fine is the 1357 sockets. I can't find ones that actually work -- seems they're all crap. Right now, I think only the tail lights are working (the sockets are very touchy). They also have to be short to fit in there.

[Barry]

I soaked mine in goof off over 24 hours, then used a scrub brush. Had to do that 2 or 3 times. Some people claim that brake fluid will do it. When I tried that, it caused the surface to be chalky which then required polishing. Surf around. Lots of ideas on how to do this.

[KPAX]

Ok, thanks, Goof Off sounds pretty easy

[cranky]

Barry said brake cleaner, did he mean brake fluid? I ask as I've read many times
be real careful when adding brake fluid if you like the paint under where you are
working, as it sill disappear. This is all - IIRC- and at my age.... we're both in
trouble here!!! GBG ... but I think the fluid is nasty...

[Barry]

Cranky,
You're correct. Brake fluid, Dot 3 or 4. I will edit my post.

[madmax]

Hi everyone, Well, I finally figured out the mystery. The problem lay in the design of the Led’s which I bought off AliExpress.
Bay 15d (1157) bulbs have two filaments & a common earth as we know. So, both are independent. Well, the way the led’s are built is not the same as the filament type.
There is only one lot of led’s in the lamp, not two & a resistor is added from one contact to drop the light output down to 5Watts. Full voltage goes direct to the pcb from the other contact to give 21watts. The resistor connects to the same point on the pcb. This means that the Voltage is being fed back on the front indicator/running lights of the bike to the indicator circuit, through the resistor or the other way around to the running lights.
So, to cure the problem I made up two Inline leads about 6” long with diodes 1N5402’s (3A-200V) in them, you can use any diodes you like as long as they can handle 2 to 3 amps to be on the safe side. One lead for each side to fit in between the front indicators/ running light connectors. Now no problems. Simple.
I forgot about this problem until I decided to replace the bulbs on my 97 model that I got earlier this year. (2024) Then again, the same problem as before on my 89 model.
I decided to keep the front running lights lit on this one. Even though it’s illegal in the UK.
Now a led had failed & I wanted to know why? It worked OK on 21W but not the 5W. So, I opened up the led, to find a resistor had burned out.
Then the penny dropped. I would have never had thought they would have used a simple resistor to lower to light output for the 5W section. Each side should be independent from the other, but they are not.
So be warned that if you fit led’s to the front indicator/ marker light you may end up with the same problem as me, especially if they come from China.
Have a good holiday & New Year.

[SgtSlag]

LED's are current driven devices: inserting a Resistor inline will lower the current, and the Lumens. Adding an inline resistor is less expensive than using a different LED device in the bulb assembly.

I hope you are not using 21 Watt LED's in your brake/signal lights!!! My LED headlight is pumping out 1,800 Lumens @ 35 Watts (the OEM halogen incandescent bulbs put out ~900 Lumens), so a 21 Watt LED tail light would be extremely bright (blinding, possibly, to motorists behind you)! The 1157 bulb is rated at 12 volts and 2.1/0.59 amps, with a power output of 26.88/7.08 watts. It produces a total of 402 lumens; an LED version of an 1157 uses only 1.7W!

Be careful when installing LED's into your bikes: you cannot judge their light output by Wattage, you have to look at their Lumen ratings, and compare them to the incandescent bulbs they are replacing. Make certain your LED replacements pump out the same Lumens, as the bare minimum. I prefer to double the Lumen output in replacement LED's, as it makes them harder for motorists behind me to ignore, as the LED's are twice as bright as the incandescent bulbs ever were!

In the USA, both flashing motorcycle brake lights (any brake light on a motorcycle, only the 3rd brake light on cages), and modulated (not flashing -- there is a distinct, obvious, difference) headlights are legal (motorcycles only). Modulated motorcycle headlights are also legal in Canada; not sure about flashing brake lights in Canada.

Both flashing brake lights, and modulated headlights, make a difference in bike visibility, based on my personal experiences, since 2006, riding both in the USA and Canada. LED headlights require an LED-specific modulator. Worth every penny, IMO. I actually had a car pull over on the road, because he saw my modulated headlight, and he thought we were Police.

We switched to the helmet-mounted Brake Free light system. It is USB chargeable; it has motion sensors; it flashes at a speed relevant to your rate of deceleration: the faster you decelerate, the faster it flashes. Fully self-contained, can be switched to different helmets. When we switch positions on the bike, we switch the Brake Free unit to the passenger's helmet. The Brake Free unit is very hard for drivers behind us to ignore -- it is v-e-r-y bright, even in the daylight... Cheers!

[madmax]

Hi SgtSlag, the led lamps that I’m on about, are the 1157 type. They are advertised as 5/21watt. Not 1.7watt. Equivalent maybe but no mention of that & no mention of the lumens in any adds for these types of lamp. Filament or Led. That’s why I didn’t mention them. I know that Led’s are current not voltage devices. But by adding a resistor you are lowering the voltage thus current, which in turn lowers the (Lumens) Brightness. Simple. That’s why the Chinese use them. Cheap & effective. Just like you said.
Most people buy the lamp that fits the socket & most people don’t know or care what’s makes the lamp work or how it’s configured inside. As long as it works. This is where on the 1200 it does matter. Especially with regards the front indicators/ running lights.
With standard lamps there is no problem.
When Led’s fitted & the running lights lit. You have voltage going through the internal resistor to the PCB & then out the other pin to the indicators & related circuit. This is an additional load the resistor wasn’t designed for.
If they were independent this wouldn’t be a problem. That’s why I had one burn out. This is why I brought this up so people that have problems don’t waste time thinking there is a problem with the bike. Just like I did. When there isn’t a problem with their bike. Just like Headlight LED’s problems, because of the reserve lighting unit. Keep things standard. No problems.
If you know of any make that overcomes this problem & are available worldwide, I’m all ears.

[SgtSlag]

I converted my incandescent bulbs on my Voyager, to LED's, around 5+ years ago. I blindly ordered, "equivalent" LED replacements, at first. I discovered that many had fewer Lumens output -- they were far dimmer than the incandescent bulbs they replaced! I only ordered red and yellow LED's as appropriate for each lens assembly. After that, I only ordered LED's I could see the Lumen count of, and only if their Lumen output was the same, or preferably higher.


I have several of the first LED's laying around, which I cannot use in any vehicle. If I cannot locate a Lumen output from the maker, I move on to another maker who does show their Lumen output. If I have to order from an overseas supplier, I will, paying the extra postage. Fool me once, shame on you; fool me twice, shame on me.

Makers might be currently making equivalent Lumen output LED's. Your best bet is to compare, side by side, your LED lights, behind the colored lenses, to verify they are as bright as the incandescent bulbs they replace. You do NOT want LED's that are dimmer than the incandescent bulbs they replaced, for safety's sake. Cheers!