LED Turn Signals

[deuce17EX]

I haven't taken the front turn signals apart yet, but do I need to buy front signals that have three wires coming out of them? Is that how they become the running lights as it is hooked into the headlight?

[mvk24_imp]

I haven't taken the front turn signals apart yet, but do I need to buy front signals that have three wires coming out of them? Is that how they become the running lights as it is hooked into the headlight?

Also unless you want to modify/drill out, etc the mounting holes for the turn signals they are an odd thread size. I remember it took me quite awhile to find LED turn signals that came in the factory thread size because I wanted to use the factory mounting locations.

I have a write up here somewhere for my micro led conversion that has the size specified. I dont remember if its an 8mm, 7mm, 6mm, etc thread off the top of my head. I used a few metal and rubber washers in the rear to mount them in the rear.

2014 CB1100, 1981 KZ440 LTD, 1993 Yamaha XJ600 Seca, 1994 Yamaha XJ600 Seca

[pekingduck]

The CB1100 turn signal system is different from older 3-wire/running light systems.
Looking at the shop manual, the front turn signals on all 2013, 2014, and 2017 models are only 2 wire. One wire goes to ground, the other goes to the turn signal/position light relay, which uses a total of 8 wires (like on the POSH units).

The relay apparently lets the front filament run at lower voltage as a running light, then at battery voltage as a turn signal, or in the emergency flasher mode. No wonder other aftermarket flashers generally can't work.

The wiring diagram says the front signals are 21 watts, and, oddly, the rears are 15 watt, with a part number specific to CB1100s. Weird.

The screws that hold the turn signals are 6mm.

[Tev62]

There are variations in other markets. My 2017MY CB1100EX does not have the front running lights feature but my now gone 2016 Africa Twin did. I see Triumph have adopted them on the 2024 Tiger 900's and my '23 GS has them. pekingduck's two wire explanation would be an easy way for Honda to programme this feature with the same wiring for different markets.

[pekingduck]

I just checked the voltage to the front turn signal, and it is 12+ volts on turnsignal, and 4.5 volts on running light. And with one front bulb out, it does not hyperflash on the 4-way flasher mode - the remaining 3 flash at the same intensity/rate as if all 4 bulbs were good.

Around 1975, when the first running light/turn signals appeared, the running lights just stayed on when the turn signal blinked brighter. Not enough contrast, so later ones turned off the running light for that side as the blinker went on.

But that required a triple throw dual position switch (DP3T?), all inside the much larger handlebar switch. Honda's new method also allows for a 4-way flasher, and removing a couple feet of wiring from each front signal and harness.

[deuce17EX]

So is it safe to assume that wiring in a couple of resistors will not be enough to convert this bike to an LED setup?

Looks like there is an updated Posh Relay on webike.... perhaps that is the route to go? I was hoping to not have to spend $87 for it!

Thanks for all the replies guys!

[deuce17EX]

i have to ask: why so hell-bent on an LED vs an incandescent?

I prefer their crisp operation, electrical efficiency, and want to match my LED headlight and taillight.

If I'm going to switch them out I might as well upgrade the technology.

[deuce17EX]

cool. good luck w it, hope it works out. this will be interesting to see how this gets resolved.

Thanks. I hope I can get it to work as well. If not, back to bulbs, but in a housing I can fit in my hand!

[deuce17EX]

can relate, why i recommended the ones i did. for future reference, these are them on my 78 KZ650. they are bright, too. and i'm running them thru a no load led flasher, so they are quick to respond unlike an old-school thermal relay.

So your flashers are a bulb but you wired in an LED flasher? What does that do to the bulb action?

[Lord Popgun]

Guys,

We went over this a while back. I posted pictures from my O’scope showing operation of the voltage from the turn signal ‘relay’. It is not a relay. It is a solid state device.

The running lights and turn signals use a pulsed DC (12 v). I don’t remember the timing, but it’s on the scope pics. Anyway, the duty cycle is such that it reads the 4.5v that Dubs read with a meter and the lights are dimmer than when turn signal is flashing. With a pulsed voltage the average voltage is lower that peak voltage.

When you select a turn signal, The duty cycle changes and the pulses are on for .5 sec and off for .5 second IIRC.

Thread with scope pics: http://cb1100forum.com/forum/showthread....#pid291206