Front Brake/stop switch

I have a '77 KZ900 and last time I rode all brake light functions were working just fine. Front brake applied, brake lights up. Rear brake applied, brake lights up. Now only my rear brake pedal will light up the brake light. Where is the front brake/stop switch located on my kz? This is the first place I want to look when I get home to see if there is any corrosion I can clean, or trace backwards.

Have a look on the lower inside of front brake fluid reservoir - just in front of where lever attaches - follow your harness - mine is a flimsy connection - had to fix it more than once. Couldn't find any diagrams so i just figured yours would be similar to mine - hope that points you in the right direction

On my 1977 KZ650-C1 the switch is on the triple tree (see image below). Sometimes if I brake hard the wires, where they connect to the switch, move a little and must be moved back for it to work again. Ed

I was able to get out for a few minutes to take a look. Ed, it appears that I also have a switch on my triple tree with bullet connectors. I had enough time to fidget with those wires only, I pulled both the hot and ground, cleaned the surface with some scotchbrite and put back on. Still did not make any difference. I won't be able to mess around with it anymore until this weekend, any other suggestions?

You should be able to use a multimeter to see if any voltage is being applied to the switch when the brake lever is pulled. Ed

Edited to correct for sleep induced mistake.

Brown is from ignition switch.

Blue runs to brake filament in rear bulb.

When ignition is ON, Brown supplies batt+ from ignition switch to front brake switch .

Application of front brake is supposed to close the brake switch (via pressure in the brake line) -- connecting Brown to Blue -- whereby Blue carries batt+ to brake filament in rear bulb.

Good Fortune!

Thanks ED ! I was a long way off

Thanks Patton, I do have a wiring diagram I was looking at, however that didn't come across very clearly when i was mentioned ground and hot. I do have a new main wiring harness that is only a few months old, I guess i'll let yall know what the multimeter says later.

Pull the Brown and Blue bullet connectors off the front brake pressure switch on front brake line junction block and short them together. I use a pair of open needle nose pliers. If the brake light comes on, you've got a bad switch. If it doesn't, break out the meter and start tracing wires.

Bama704 wrote: Thanks Patton, I do have a wiring diagram I was looking at, however that didn't come across very clearly when i was mentioned ground and hot. I do have a new main wiring harness that is only a few months old, I guess i'll let yall know what the multimeter says later.

There is no "ground" involved at the front brake pressure-activated switch.

Whenever the ignition is ON, Brown is supplying batt+ from the ignition switch to the front brake switch, regardless of whether the brake lever is being squeezed or not being squeezed.

In other words, whenever the ignition is ON, there should always be batt+ via the Brown wire connection at the front brake switch.

Only when the front brake switch is activated (closed) by pressure in the line (due to squeezing the brake lever) does the Blue wire then carry batt+ to the brake filament in rear bulb.

Whenever the ignition is ON, squeezing the brake lever simply closes the brake switch (connects Brown and B lue) which simply extends Brown batt+ via the Blue wire to the brake filament in the rear bulb.

The front brake switch has no ground. It simply allows or disallows Brown's batt+ via Blue to the brake filament in the rear bulb.

The ground for the brake filament in the rear bulb is a via a black/yellow wire to the chassis.

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Got the issue fixed, it was a faulty switch. Luckily I was able to pick one up yesterday from a guy who has a riders paradise of bike parts. While I was there he showed me a KZ1000 he was working on. It needs a new paint job, but will look killer when repainted.

Good Fortune!