Clutch's 1982 KZ750 E3 Cafe

You did a good job with your bike, and now your getting the reward of riding. Hope the weather there stays good for you, have fun.

Motor Head wrote: You did a good job with your bike, and now your getting the reward of riding. Hope the weather there stays good for you, have fun.

Thanks

The weather is gradually getting chilly here. It was pretty nice today, but I know the "too cold to ride" (for me) weather is coming soon. Hopefully I can figure out the issue with my tail light and get in a few more rides before storing for the winter. At least I still have plenty left to do on my '66 A1 project. LOL

I was playing around with the tail light today, and it seems that the only time I have issues with the thing going out is when the ignition is running. I'm thinking that the way I have it wired will require a relay for the ignition, and hopefully that will fix the tail light issues I am having.

What is this an LED tail light assy? How's it wired, since you did your own wiring? Where is the feed for the power coming from, ignition switch, through fuse panel, to the brake switch, to the light? Then Tail is switched with the head light?
Measure the voltage where you connected the new light, using first the ground wire, then the chassis for the negative meter probe. Both Tail, and Brake. Then un-plug the brake wire from the light, then test there for power when the tail is on. Then reverse that, un-plug the Tail wire and test there when the brake is on. To see if it is back feeding. Could be a Diode issue.

There is a main fuse, then ignition switch. From the ignition switch, there is one main power wire going to a fuse block that powers everything. Since the ignition is so taxing, and the LED has low draw, I figured that I created a "load dependent" tail light circuit. This is why I was thinking that the relay may fix the problem. I will still run the meter testing, but will probably get the relay anyway.

Motor Head wrote: What is this an LED tail light assy? How's it wired, since you did your own wiring? Where is the feed for the power coming from, ignition switch, through fuse panel, to the brake switch, to the light? Then Tail is switched with the head light?
Measure the voltage where you connected the new light, using first the ground wire, then the chassis for the negative meter probe. Both Tail, and Brake. Then un-plug the brake wire from the light, then test there for power when the tail is on. Then reverse that, un-plug the Tail wire and test there when the brake is on. To see if it is back feeding. Could be a Diode issue.

I didn't do the unplugged part, but the brake side reads less than 1v (about .78v) when the tail only is on. The tail light reads battery voltage when brake is on, but I that is with it plugged into power. I will try the unplugged part next time I go out for a smoke. Hopefully it's not the light itself. I've only had it about a year and a half, so I would hate to be replacing that already!

Clutch, just when im reading this i'll ask the question now.

I have an LED stop/tail light to fit & I'm hoping to wre it like this. Banjo bolt brake light switches for front & rear brakes both wired into the same relay to activate it. The power wire will then activate the stop light when the brakes are hit?

I've read some LED stuff about resistors & its messing my head up! :lol:

750steve wrote: Clutch, just when im reading this i'll ask the question now.

I have an LED stop/tail light to fit & I'm hoping to wre it like this. Banjo bolt brake light switches for front & rear brakes both wired into the same relay to activate it. The power wire will then activate the stop light when the brakes are hit?

I've read some LED stuff about resistors & its messing my head up! :lol:

The relay should work as you described, but it shouldn't be necessary with the stock wiring. I had mine hooked up with stock wiring and it worked fine.

You can also do a Bench test, off or on the bike. With some test leads to the battery, taking the other switches and wiring out of the equation.

With the brake light wire disconnected, it still reads .78v with the taillight on. Is this indicative of a bad diode?

clutch wrote: With the brake light wire disconnected, it still reads .78v with the taillight on. Is this indicative of a bad diode?

Is this with the wire coming out of the Light assy, with the brake wire disconnected from everything?
Sure sounds like a Diode failure/ Leak. I don't know exactly what circuitry they use in the Assy, but if you can get the Assy apart to look at the circuit/ board. You can test the diodes, get a replacement for cents.
Of course each 1 of those bulbs/ LEDs is a diode.

Motor Head wrote:

clutch wrote: With the brake light wire disconnected, it still reads .78v with the taillight on. Is this indicative of a bad diode?

Is this with the wire coming out of the Light assy, with the brake wire disconnected from everything?
Sure sounds like a Diode failure/ Leak. I don't know exactly what circuitry they use in the Assy, but if you can get the Assy apart to look at the circuit/ board. You can test the diodes, get a replacement for cents.

Ok I will pull the light off sometime soon, and post a pic of what I see (I will have no clue lol). I'm searching eBay for tail lights atm to see if there is something I like better than what I have though.