Problem with LED running/brake/turn signals lights

I have a 1980 KZ 1000 LTD, with Vetter fairing and luggage, i.e., trunk and side bags. I have two running/turn signal lights in the front (fairing), and four turn signals in the rear. Two running tail/brake lights (on the trunk), plus the bike's tail/brake light. I just replaced all the old incandescent bulbs with new LED's. they all work other than my instrument panel brake light stays on all the time (telling me I have a brake light out) which I don't. I'm assuming the LED's aren't using enough electricity to tell the sensor that all my brake lights are working. (Normally the instrument panel brake light only comes on when you apply the brakes. It stays on all the time now). PLUS the brake lights aren't that much brighter than the running lights. Anyone have any suggestions?

Capt__ wrote: I have a 1980 KZ 1000 LTD, with Vetter fairing and luggage, i.e., trunk and side bags. I have two running/turn signal lights in the front (fairing), and four turn signals in the rear. Two running tail/brake lights (on the trunk), plus the bike's tail/brake light. I just replaced all the old incandescent bulbs with new LED's. they all work other than my instrument panel brake light stays on all the time (telling me I have a brake light out) which I don't. I'm assuming the LED's aren't using enough electricity to tell the sensor that all my brake lights are working.

Almost for sure. The low impedance of the brake light bulb filament (like ten Ohms) tells the sensor to stay dark. The LED impedance is high enough that the sensor doesn't see it so it reports a blown filament.

Capt__ wrote: PLUS the brake lights aren't that much brighter than the running lights. Anyone have any suggestions?

lack of brightness is the chronic plague of most LED tail lights. I only know of a couple that are as bright as 1157 incandescent bulbs.

Capt__ wrote: ... instrument panel brake light stays on all the time (telling me I have a brake light out) which I don't....

While brakes aren't being applied, a "blinking" instrument panel brake light is warning that the brake won't shine when brakes are next applied.

When brakes are being applied, the constant red instrument panel brake light is showing that its own little bulb is functioning.




Good Fortune!

The rear brake light switch is activated by a spring assisted linkage to the foot pedal.
The spring prevents damage to the switch by limiting the amount of pulling force applied to the switch through the linkage.






When the ignition is ON, a brown wire furnishes battery positive voltage to one end of the rear brake light switch.
A blue wire connects the other end of the switch to the brake filament in the rear light bulb.

When a properly functioning switch isn't being pulled, the brown and blue wires aren't connected, and battery voltage isn't passing through the switch.

When a properly functioning switch is being pulled, it connects the brown and blue wires, whereby battery voltage from the brown wire passes through the blue wire to the brake filament in the rear light bulb.

The linkage between the pedal and switch is adjustable so that the switch is pulled when the pedal is depressed, and isn't pulled when the pedal isn't depressed.

If the switch linkage is maladjusted too loosely, depressing the pedal won't activate the switch.

If the switch linkage is maladjusted too tightly, the switch is continuously and erroneously telling the instrument panel light that the rear brake is being applied (i.e., that the pedal is being depressed), even when the rear brake isn't being applied.

Similar principles apply to a properly functioning pressure-activated (brake fluid inside the brake line) front brake switch, which allows voltage to pass through the switch when the front brake is applied (pressurizes the switch), and disallows voltage from passing through the switch while there's no pressure inside the brake line (front brake not being applied)




Good Fortune!

I had the same problem in my 78 kz1000. I tried LEDs in the instrument cluster and indicator lamps and my brake indicator acted the same way. My neutral light also did not work correctly. I believe you have to put in a resistor for the circuit to work properly. with LEDs,...but not sure. Some of the LED vendors provide an inline package for the LEds to work in the old circuits. I gave up and put the incadecent lamps back in and they worked fine again. So the actual circuit was fine. I found that the LEDs were not birghter and am happy wiht the original lamps.

Besides the small spring linkage that connects the pedal to the switch, there is also a larger more powerful spring that returns the depressed pedal to its normal un-depressed riding position (as set by the adjusting bolt).

If the pedal pivot is sufficiently rusted and corroded, the return spring may not be powerful enough to return the pedal to its normal riding position.

Good Fortune!

yes, i understand all that thank you. All lights (including the brake light on the instrument panel) work fine, while using the old incandescent bulbs. But when I replaced with all new LED lights, the brake light bulb on the instrument panel now stays on constantly. Any thing to offer on that?

thanks, I've seen the suggestions about adding a resistor. That's kind of defeating the purpose. I'm trying to REDUCE electricity usage. My bike is old, and there is some degree of wiring fatigue. More frequently than it should, it blows the main fuse, and I've noticed the wiring is warmer than it should be. I've bypassed the OEM fuse box and put in solitary fuses for the individual circuits. That helps but I'm still trying to lower the energy usage. Back when this bike was built (1980) we didn't have cell phone charges and multiple exterior lights, or at least it wasn't built to accommodate such. I'll share if I figure anything out... Thanks again!

Yup....The warning circuit for the brake light will not accommodate LED's. Just immersed myself in this circuit this week.

When the brake is not applied, the circuit is expecting to see ground through the incandescent tail bulb. If the bulb has gone "open", then the circuits sensing wire floats high, and kicks on the flasher circuit to the dash. Put an LED in the tail, and the sensor wire cant see thru it to ground anymore and thinks the bulb is gone.

I think adding a resistor across the light will make it work somehow, and it may be that a high value resistor may be fine (say 1K ohm)...just enough to bleed the sensor down to ground. Would be worth playing with.

Cheers
Chris

Just thinking a bit more on this....

the warning circuit is idle powered by 12V coming from the indicator light on the dash. To make the light on the dash illuminate, it provides a path to ground.

If the dash light is an LED, I don't think the circuit can get its 12V it needs to work. So at best, I believe you need an incandescent in the dash and then play with the largest value resistor in the tail to make it work.


If your wires are "warm"....I think spending the time finding the true issue would be a good investment. Resistive (corroded) connectors can make wires hot.

Cheers
Chris

No eBay APP ID and/or Cert ID defined in Kunena configurationI installed led signals on my hayabusa and my ex 500 :S .........you have to install a small resistor :ohmy: ..... these should correct your issues.
first set I found on flea bay