KZ900 dash panel brake light flashes

After 15 months I have finished rebuilding and modifying my '76 KZ900(photo attached). Seems like a long time but I gotta work to pay for it all
The one problem I am having trouble tracking down is that when I turn on the headlight, with just the key turned to on position or bike running, the brake light dash indicator flashes. All the wiring is new. I've replaced the rectifier & regulator with the newer single unit. Everything else works fine. Any suggestions would be appreciated.

Did you replace your taillight with a LED bulb? I have a Yamaha that thinks the lite is burnt out when I run a led bulb in it

I have a LED strip on my top box and it glows dimly but goes bright when I hit the brakes. Might be the problem.
Steve

900Kawpen wrote: After 15 months I have finished rebuilding and modifying my '76 KZ900(photo attached). Seems like a long time but I gotta work to pay for it all
The one problem I am having trouble tracking down is that when I turn on the headlight, with just the key turned to on position or bike running, the brake light dash indicator flashes.

These bikes have a sensor circuit that uses the low impedance of the brake light bulb filament (which is a few Ohms) to keep that flasher from occurring. If the bulb blows out and the filament is open, you see the flasher on the indicator. The bulb is blown, disconnected, or may have been replaced with an LED type which has a much higher impedance and will allow the indicator to flash.

The flashing brake light indicator is warning that the rear brake light will not come on when the brakes are applied.

The typical reason is a blown brake filament in the stock rear light bulb.
Another reason might be a loose or corroded connection at the bullet connector under the seat (over the rear fender) where the brake light harness wire connects to the wire going to the rear light.

Good Fortune!

bountyhunter wrote:

900Kawpen wrote: After 15 months I have finished rebuilding and modifying my '76 KZ900(photo attached). Seems like a long time but I gotta work to pay for it all
The one problem I am having trouble tracking down is that when I turn on the headlight, with just the key turned to on position or bike running, the brake light dash indicator flashes.

These bikes have a sensor circuit that uses the low impedance of the brake light bulb filament (which is a few Ohms) to keep that flasher from occurring. If the bulb blows out and the filament is open, you see the flasher on the indicator. The bulb is blown, disconnected, or may have been replaced with an LED type which has a much higher impedance and will allow the indicator to flash.

I think you're right but that doesn't explain my light glowing dimly.
Steve

I did install an integrated LED taillight and headlight on the bike. Along with the dash panel brake light flashing with the headlight turned on the turn signals hardly flash...super slow. Any electrical guru's have a suggestion ?
Always appreciate the help from this forum

I installed a relay for my coils and one for my horn. I was thinking of installing one for my running lights too. I'm ordering some 1157 LEDs today. I might have a problem with the turn signals though. It might help if you isolated your head light with a relay. $15
Steve

swest wrote:

bountyhunter wrote:

900Kawpen wrote: After 15 months I have finished rebuilding and modifying my '76 KZ900(photo attached). Seems like a long time but I gotta work to pay for it all
The one problem I am having trouble tracking down is that when I turn on the headlight, with just the key turned to on position or bike running, the brake light dash indicator flashes.

These bikes have a sensor circuit that uses the low impedance of the brake light bulb filament (which is a few Ohms) to keep that flasher from occurring. If the bulb blows out and the filament is open, you see the flasher on the indicator. The bulb is blown, disconnected, or may have been replaced with an LED type which has a much higher impedance and will allow the indicator to flash.

I think you're right but that doesn't explain my light glowing dimly.
Steve

Hard to say without a schematic. Mine uses a 555 timer circuit, the IC may be blown.