TOPIC:

Hi, my brake light stopped working and so far I’ve changed the bulbs, put on a new front brake switch and a new rear brake lever switch/ cable and I’ve traced the wires and renewed the connectors etc, I now have a constant brake light on situation, what have I done??

You don't provide much information on the year or make of bike but most bikes have a two filament bulb with one always on to illuminate your plate and the other to act as your brake light.

Hi, the bike is a KZ750 spectre n1 spectre 1982, it has stop and tail bulbs, the tail light is working fine, the brake light stopped working on both front and rear brake but I now have the brake light constantly illuminated unless I unplug it.

Make sure the light bulb socket is clean, corroded or rust sockets can back feed tail light power to the brake filament 

Have you try to disconnect the new F/R break light switches to solve your permanent break light problem?
Most rear break switches attached to the foot leveler need some adjustments to the work properly.

Thanks, will check.

Hi, I tried disconnecting the front switch which made made no difference, the brake light remains on, I’ve also tried putting back on the old front and rear switches which again makes no difference, the only time the brake light goes out is if I disconnect the blue wire, at least I know the problem isn’t faulty wiring or bad earth, there doesn’t appear to be any adjustment on either the rear switch cable or on the spring, the only nut is the one that secures the lever joint to the master cylinder.

Just for kicks
Run a wire from your ground terminal on the battery to the black/yellow connector in the pink circle.
most likely not the issue

schematic courtesy of:
www.classiccycles.org/1852/597943.html

I’d check the rear wiring harness for pinched or wires with insulation worn off. Somehow you get power from the red wire to the blue. Do the brake lights come on when the ignition is turned on?

what happens if you disconnect just the rear switch?
 

wrote:

what happens if you disconnect just the rear switch?

 

Thank you for posting the link to the schematic site. Great resource 

Hi, yes the brake light comes on when I turn the key along with the tail light.