Topic: Running LED (front) SIGNALS... I've tried everything, nothing is working. HELP?

[CB750Noobie]

I'll start by apologizing for writing another one of these wiring posts-- but I am at a standstill here...  I've read as many as I could find, and tried their advice. Nothing has worked.
 
I'm trying to wire front LED turn signals (only front, for now) to my 1981 Honda CB750 K DOHC. Please see below and let me know your thoughts. I'm no electrical engineer, but I understand basic wiring and power supply and have wired LED signals/brake lights in the past. I have no idea why this is not working... 

Bike: 1981 Honda CB750 K Four DOHC (North American model)
Wiring is as follows:

Blue - Right signal
Orange - Left signal

Blue White (2 wires into 1) single male bullet connector - Right signal indicator light (dash)?
Orange White (2 wires into 1) single male bullet connector - Left signal indicator light (dash)?

Two separate Green (ground) into 2 bullet receiving female connector.

Two separate Green (ground) into 2 bullet receiving female connector (there are 2 of these, yes).

The OEM incandescent signals had a green, blue, and blue white wire (3 wires off of each signal). Respectively the other side then had green, orange, orange white.  The new LED signals have 2 wires. One has the Blue+ and Green-, the other has Orange+ and Green-
Seemed simple enough.

What I've bought:
A new flasher relay-- NOT sure if it's LED compatible... this is the next thing I'm ordering... again

Diode --> two red+ male bullet connectors into one white female connector (one diode)

Bikemaster Resistors --> Black female bullet receiver (-), black male bullet (-), red female bullet receiver (+), red male bullet (+)
(2 of these resistors in a pack)
https://bikemaster.com/motorcycle-replacement-parts/turn-signals/cylinder-resistors.html

This article would be substantially larger if I told you every wire combo I've tried, spliced, etc... and my results were that I had the indicators flashing for each side correctly with the resistors, but a solid (single) indicator light then... so I undid it and tried some other nonsense. NOW, no matter how I redo it, I cant get ANY lights flashing (even putting them back exactly how I had them, I just get solid lights both sides on. Nothing results in a flash. During my experiments I did get a light spark and blue a fuse on the bike and replaced it. Wondering if this somehow damaged the resistors...? Can anyone help?

I can definitely take pictures if needed.

[Bankerdanny]

I'd have to track down a DOHC wiring diagram to offer specific advice for your bike. But I will offer this generic advice: you have a modern solid state flasher you should not need resistors if you are still running incandescent bulbs in the back. I run this setup on my bike and they flash fine as long as the battery condition is fine or the bike is running. With the engine off the lights won't always flash.

[HondaMan]

Generally speaking: to run LED lamps successfully you need to use an all-electronic flasher unit, like those found in cars. They are also BIG. These units flash whether the LEDs draw power or not, so don't get the type with a relay inside or it will just wear out. It also requires 3 wires to it: one is from your Green Ground, one comes from the power supply - this is the L-R Flash wire (usually GREY on most of the bikes, but not always) and the one that goes to the L-R switch to select sides.

[CB750Noobie]

I'd have to track down a DOHC wiring diagram to offer specific advice for your bike. But I will offer this generic advice: you have a modern solid state flasher you should not need resistors if you are still running incandescent bulbs in the back. I run this setup on my bike and they flash fine as long as the battery condition is fine or the bike is running. With the engine off the lights won't always flash.

Right! This is what I saw everywhere online- however, I was testing the new LED (front only) signals with the motor off (because the carbs, intake and exhaust are currently off the bike as well). I would never have thought that the bikes motor being off would effect the electronics since they're still firing hot signals to where they need to be. And again with the resistors, I had it right... and the signals flashed completely fine (no hyperflashing) but with solid indicator light. And then when I experimented more, and failed, and then tried reverting it... and now nothing flashes, ever. No matter how I change the wiring.

I've seen people who have had the same 'all 4 lights on, no flashing' on youtube, and they've installed upgraded LED flasher relays on their bikes (one was even a newer earlier 2000s Kawasaki ninja) and it fixed their problem. So maybe this could work for me? But I was under the impressions that a diode or resistors eliminated the need for the relay. 

[mrbreeze]

My bike has been on the back burner for the last few years due to family health problems and an out of state move 2 years ago. I'm about to the point where I can finish it up hopefully before the snow flies and get a few rides in. One thing I was working on was putting LED's in my dummy lights and I was having problems making it work. I scoured the forum and various wiring diagrams and have come to the conclusion it will be easier to run the dummy lights with stock bulbs. I will however keep the LED's in the gauges. I like the brightness they provide plus blue bulbs. The only problem I had on the dummy lights was the turn signals. Besides that I just have to go through the carbs and reinstall. Went from sea level to 7000 ft. so will have to move the needles and go down on main jets. I had it apart for cam pucks, paint and Gordon frame kit. That stuff was all done 2 or 3 years ago. Carbs & coils, turn signal wiring and I should be good to go.

[gtmdriver]

LED lights don't draw enough current to operate a conventional (bi-metal strip) flasher unit.

Your best bet is to use an electronic flasher unit which flashes at a constant rate regardless of current draw.

If you are retaining filament type bulbs in the system too the you need a high capacity electronic unit. I have one on my CB350F and it works brilliantly.

[CB750Noobie]

LED lights don't draw enough current to operate a conventional (bi-metal strip) flasher unit.

Your best bet is to use an electronic flasher unit which flashes at a constant rate regardless of current draw.

If you are retaining filament type bulbs in the system too the you need a high capacity electronic unit. I have one on my CB350F and it works brilliantly.

I just ordered a new LED specific flasher unit that I will be trying out. Man I hope this alleviates this headache.

Thank you for everyone input. Best of luck with your continued build MrBreeze... yeah I put all new gauges on with LED lights, and those all work completely fine for me!

[Dolomite]

I converted every bulb on mine to LED, including potting ones into the handlebar style pilot lights. If you use the flasher unit made for LEDs you do not need resistors. I have no resistors in my setup, only diodes on the signal lights so that they don't operate both at one time. I can try to get you some photos this weekend if you think they'll help.

[Xander^]

Currently having the same sort of issue.. just installed an LED rear flexi taillight with signals intergraded from dime city cycles and the signals dont flash, they light up and stay lit. My front also generic LED signal indicators, also don’t work at all.. got a LED flasher relay on the way but lets see if that works.. i had one in there before apparently but think i needed this new one i just ordered>>>

Keenso 2 Pin 12V Universal Motorcycle Electronic Turn Signal Flasher Relay Speed Adjustable LED Flasher Fix Motorcycle Turn Signal Hyper Flash(Black) https://www.amazon.ca/dp/B07JW1FGF8/ref=cm_sw_r_cp_api_i_4E4SEb4W6ASN8

[Deltarider]

This replacing by LED has become an epidemic in this forum. On European fora nobody does it. Why would you? It results in a lot of hassle, extra parts needed, indicators less noticed (no dynamic glow on, glow of) and brightness only in one direction. Then the claimed longer longevity. Really? Why is it then that I see quite some cars with LED DRLs where only one side is lit? On my bike the two rear indicator bulbs are still the same as in 1976. In front I have replaced them by these, because I don't like amber (for safety they flash amber though

[Dolomite]

This replacing by LED has become an epidemic in this forum. On European fora nobody does it. Why would you? It results in a lot of hassle, extra parts needed, indicators less noticed (no dynamic glow on, glow of) and brightness only in one direction. Then the claimed longer longevity. Really? Why is it then that I see quite some cars with LED DRLs where only one side is lit? On my bike the two rear indicator bulbs are still the same as in 1976. In front I have replaced them by these, because I don't like amber (for safety they flash amber though

How is this helpful or constructive to the topic? He didn't ask for a debate on LED efficacy, he already decided he wants to change to LED and is asking for help, not a diatribe on why innovation is bad.

[rotortiller]

Pretty basic stuff especially if you have both left and right monitor lights. Try one of these, I've used it with 12 volt led signals on vintage bikes.

[Deltarider]

This replacing by LED has become an epidemic in this forum. On European fora nobody does it. Why would you? It results in a lot of hassle, extra parts needed, indicators less noticed (no dynamic glow on, glow of) and brightness only in one direction. Then the claimed longer longevity. Really? Why is it then that I see quite some cars with LED DRLs where only one side is lit? On my bike the two rear indicator bulbs are still the same as in 1976. In front I have replaced them by these, because I don't like amber (for safety they flash amber though

How is this helpful or constructive to the topic? He didn't ask for a debate on LED efficacy, he already decided he wants to change to LED and is asking for help, not a diatribe on why innovation is bad.

The answer is simple. Often topics in this forum occur in waves. Every now and then there's hysteria on zinc, then there's the charging system which isn't a problem elsewhere. Don't you think Honda would have noticed and modified things on later models? They had years for it! Whether you like it or not, we tend to infect one another. Can be good, can be not so good. If I reply, I also have others readers in mind that wonder if replacing is needed.
When somebody suspects the stator being the cause and Bryanj woulde react with: in all of my career, I have never seen that part fail, don't you think that's useful information? The dealer I had in the 80s was in the same category. "You don't need that", was his standard reply. He could have earned a lot more money from me. It's the same with this replacing by LED. It often causes more problems than it solves (just do a search here). If I would give further info on how to deal with that replacing, I'd feed the assumption it is an useful modification, which it is not. It just satisfies the desire to play with your bike and as such falls in the same category as adding an unneeded extra inline fuel filter that often also causes more problems than it solves. I might not have helped the OP, but I might have helped others. Thats what a forum is for.

[CB750Noobie]

I converted every bulb on mine to LED, including potting ones into the handlebar style pilot lights. If you use the flasher unit made for LEDs you do not need resistors. I have no resistors in my setup, only diodes on the signal lights so that they don't operate both at one time. I can try to get you some photos this weekend if you think they'll help.

That would be absolutely awesome man (and thanks for covering the comment below by the way ). I have full LEDs on my new Triumph Bonnie, never had to wire in diodes. I've watched enough videos for them to make sense, but if you can provide pictures that would be really appreciated and helpful. Thank you for chiming in!

[HondaMan]

My bike has been on the back burner for the last few years due to family health problems and an out of state move 2 years ago. I'm about to the point where I can finish it up hopefully before the snow flies and get a few rides in. One thing I was working on was putting LED's in my dummy lights and I was having problems making it work. I scoured the forum and various wiring diagrams and have come to the conclusion it will be easier to run the dummy lights with stock bulbs. I will however keep the LED's in the gauges. I like the brightness they provide plus blue bulbs. The only problem I had on the dummy lights was the turn signals. Besides that I just have to go through the carbs and reinstall. Went from sea level to 7000 ft. so will have to move the needles and go down on main jets. I had it apart for cam pucks, paint and Gordon frame kit. That stuff was all done 2 or 3 years ago. Carbs & coils, turn signal wiring and I should be good to go.

Hint: leave the needles alone and drop 5 on the mainjet if it is above 105. If it is already 105 then you are fine, just run on Regular gas instead of higher otanes. I live at 6000, works out fine to 8500. Above that it gets a little less effective, so hold the RPM abou t500 higher on average to keep it clean when climbing Mt. Evans or Pikes' Peak.