Successful LED Signals with Auto Cancel and No Resisters

I have been having a few problems converting to LED turn signals in that the LEDs would not flash and all 4 LED turn signals would light at the same time. The flash failure is a well known problem cause by the high resistance of the LEDs not drawing enough current to activate the stock flasher. The problem with all 4 LED turn signals lighting at once is due to feedback between the left and right turn signal circuits thru the dash turn signal indicator bulb. My solution was to use the superbrites.com LSF-1 "no draw motorcycle LED flasher" and modify the dash indicator bulb circuit.

Note that much of this post is also in my final post in the "LED Turn Signal Problems" thread but I thought enough people would be interested in a successful LED installation that it deserved its own thread.

I installed the superbrites LFS-1 flasher 12V lead to original flasher brown wire and Load lead to original flasher brown/white wire and all 4 signal LEDs flashed whenever the turn signal switch was activated in either direction; as I expected it would due to feedback thru the dash indicator bulb.

Took a run to Radio Shack and picked up 2 rectifier diodes (100V/3A) for $1.69. In the headlight I unplugged the dash connector and pulled the 2 metal fittings (dark green and dark brown wires ) for the turn signal indicator bulb from the connector attached to the main wiring harness and clipped off the metal fittings with about an inch of wire attached. To the fitting with the dark green wire I soldered the ends of both diodes. To the other end of one diode I soldered the dark green wire just cut from the fitting and going into the main wire harness. Then I cut the fitting off the dark brown wire leaving about an inch of wire on the fitting. Next I soldered the dark brown wire just cut from the fitting and going into the main harness to the other diode.

The fitting with the green wire is reinserted into the connector where it came. I then soldered a black wire to the inch long dark brown wire attached to the other fitting and installed the fitting into the connector from where it was removed. The other end of the black wire is connected to ground.

Reconnect the 2 ends of the dash connector pulled apart earlier and test the turn signals.

Note that all soldered fittings were pre fitted with shrink wrap prior to soldering to cover all splices.

Viola! Each side blinks independently and the dash turn signal indicator bulb is bright and clear.

For an added bonus I disconnected the FS1 flasher and reinstalled the original flasher and then wired in the FS1 flasher in series after the original flasher and now I have auto cancel with no ballast resisters. (wire the 12V lead of the FS1 to the L terminal of the original flasher and then the L terminal of the FS1 to the brown/white wire that was originally attached to the original flasher L terminal.

hi forest, thanks for all of the diligent work on your leds and the instructions for us, im tackling mine now. i have a tail light with integrated turn signals, i was wondering if you have or anyone else have drawn a diagram for this assembly? i know nothing about wiring and have yet to get power to the lights after plugging them in, i do though know that they work because i checked them against the battery. ...but my problem my be deep maybe not. thanks

Are you using standard wiring (other than the new tail light)? So .... you have 5 lights in your tail light: Running light, liscense light, stop light, right turn, left turn. First step is identifying which original wire is supposed to go to each light. Check your fuses and the fuse box. The fuse boxes deteriorate and might need to be replaced even if the fuses are good.

Which of the 5 lights do not work?

well, the fuse box has been replaced. the signals and the brake light worked with the exception of one signal the was missing all together, when i took off all the fender assembly all i really did was unplug all the stock wiring havent cut anything so i tbink it all works except the headlight. still trying to figure that one out but there seems alot of guys and girls here have that issue. ive also unplugged the gauge for the all in one speedo, with warning lights so maybe i should plug back in the stock untill i get this figured?

Start with plugging all the stock stuff back together. Once you get the stock stuff working you can methodically unplug stuff one at a time and test what affect unplugging that one thing has on you system. There is a headlight relay mounted near the battery that is often a source of problems. Sometimes they burn out but more often just get full of dirt and bugs and cobwebs. I haven't had to do it on the xs400 but I've pulled the cover off many relays and cleaned out the insides and cleaned up the contacts with an emery board and got them working just fine. That being said, some relay covers cannot be removed.

You say "the signals and the brake light worked". Did they work before or after adding the new tail light, or both? If you can locate the wiring for the missing signal light you should be able to test if you have voltage after turning on the signal by using a meter. If you don't have a meter .... get one. A half decent digital volt meter (DVM) can be purchased at Sears for around $25. It will be invaluable in diagnosing electrical problems.

i have a meter but dont really know how to use it, i will learn through this forum. currently i have no power to any of the lights except for the neutral warning light and the oil pressure light. i will plug in all my old gauges then test them but as i remember they only worked sporadically. i noticed that all the lights work through a common ground. do you know off hand where the problem might be? i will source a new head light relay hopefully that helps but i am sceptical because the indicators did work intermittently before i removed them, but he head light has never worked. by chance can you post a pick of it and the headlight relay? i believe i have found it, its under the tank close to the forks. sealed.

The headlight may actually be burnt out. Your meter should be able to tell you ar least 2 things when set and used properly 1) you have voltage to the light 2) the wires are not broken. To practice test for voltage set the meter on the V setting ar the setting just higher than the voltage you expect. For example , your motorcycle works on 12V so set the meter to read the next highest V range which is likely to be 20V. Place the red lead on the battery + terminal and the black lead on the battery - terminal and the meter should read 12V. (make sure the battery in the meter is not dead before starting).

Can't post pick of the relay as our bike has a custom seat and side covers that are tough to take off.

You will also need a wiring diagram for your bike. Search this forum and download one. That is where I got mine.

Although ground is "common", there are several ground points on the bike: from memory, one or more in the headlight, one by the rear lights, one by the battery.

To start troubleshooting your headlight: use the wiring diagram to follow the voltage from the battery to the headlight and test fro 12V at each connection from the fuse to the headlight to see where the 12V stops.

in progress

Re: Successful LED Signals with Auto Cancel and No Resisters
i have a meter but dont really know how to use it, i will learn through this forum. currently i have no power to any of the lights

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Start you own thread if you not chatting about Successful LEDS, you have moved into Troubleshooting, Start with The Tech section, Manuals, and Search functions. Pay attention to the RE-WIRE segment. (you dont have to re-wire the whole bike, just use the tips and tricks listed. Between google, and Youtube you too can learn "how to use a multimeter" I make it easy for you. http://www.lmgtfy.com/?q=how+to+use+a+multimeter

Hijack Complete On to my question!

Took a run to Radio Shack and picked up 2 rectifier diodes (100V/3A) for $1.69. In the headlight I unplugged the dash connector and pulled the 2 metal fittings (dark green and dark brown wires ) for the turn signal indicator bulb from the connector attached to the main wiring harness and clipped off the metal fittings with about an inch of wire attached.

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Have you any photos? I seem to remember one out there, I don't remember how long ago?
if it was yours, or someone elses?
Thanks Tobie

ps Thanks for resurrecting this thread.

Sorry, no photos of this specific task. Photo album of the build here:
http://s256.photobucket.com/user/jmd_forest/library/1980 XS400 Cafe Racer Build?sort=6&page=1

That's cool man. I know there have been a lot of problems trying to successfully do this.

Thx for all the help guys, ive started a new thread, re. Wiring trouble shooting ;-)

Hi does any one know how to wire up an led tail light with intigrated signals? It has five wires coming from it . One groung, one park/running, one brake, one right and one left. I understand the need for resistors. And the ones that i have 4 wires two from each side of the resistor, one side is black the other yellow and there is no direction indication on them. Thx guys oh and my wiring is stock, 79f or f2 t.

If you are still using stock front signals I THINK you can simply connect the old wires to the cooresponding new wires and it will work without resistors.

Im not planning to use the stock signals; only the signals built in to the tail light. Problem is that there is o.ly a single ground wire coming from the whole aparatis.

here is the product im trying to install, http://www.kapscomoto.com/product_p/tl-gj-022-1m.htm
there is a plug and play version for triumph and ive seen this tail light on another older bike 1980 honda. so im guessing is possible. any help appreciated

Specification:

Quantity: 1
Lens Color: Clear
Lights: LED
Instructions: not included

Tail Light Fitment:

Complete Custom Application
Modification may be required
Wire Set-up
ground = black
running light = green
brake light = red
left turn signal = orange
right turn signal = yellow

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It says not included. Okay, It is possible. How ever till you have everything functional, in its normal ways. Your are getting in over your head. Did you get the 2 rectifier diodes for the turn signal? I have no doubt you can get that to work on our bike. You will find all the wires there. do some pre planning, get the right connectors, with out the plastic coverings, so that you can put a dab of Solder on to each connector point, for the best connection(after you crimped it with the good crimper.) Plan on some mistakes, and get the heat shrink tubing for the water tight connections.

I know on mine I just used brake leds, rear turn leds, upgraded xenon headlight, left the front turn's stock and everything worked as it should without doing anything.

Actually thats just what im doing also but the brake light and signals use only one ground round for all three

I have been wrong before.

The single ground should work just fine for all the lights in the new tail light. As arfstrom provided, hook up the original hot leads from the bike to the cooresponding wires in the new tail light. Hook up the ground from the new tail light to ANY ground wire and it should work.