TOPIC:

I had to replace my front brake master cylinder and therefore front brake due to various nonelectric problems. The brake light worked with the old, stock lever/perch. However, now when I connect the same two wires that go to the brake lever, there is no change in the intensity of the tail light; ie, the brake light isn't turning on.

I think I understand that both wires that go to the lever are positive. I bought a new master cylinder that uses simple male plug tabs instead of the OEM cylindrical connector. I'm at a loss here, electrical is not my forte.

DontFallTim wrote: I had to replace my front brake master cylinder and therefore front brake due to various nonelectric problems. The brake light worked with the old, stock lever/perch. However, now when I connect the same two wires that go to the brake lever, there is no change in the intensity of the tail light; ie, the brake light isn't turning on.

I think I understand that both wires that go to the lever are positive. I bought a new master cylinder that uses simple male plug tabs instead of the OEM cylindrical connector. I'm at a loss here, electrical is not my forte.

Does the brake light work with the rear pedal?

Have you tried reconnecting the wires to the old perch (just for testing purposes)?

Have you tried reversing the polarity on the wires? It always worked for Geordi La Forge.

I can't get to the bike right now, so I'll correct this tomorrow if I'm wrong, but no, the rear brake never turned on the brake light and still doesn't.

I don't think the old perch will receive the wires as they are. The cylinder was replaced a couple weeks ago. Pretty sure my buddy and I lost the connector in the rush (clipped the old connector off when we saw the new perch used a different type) to get the front brake working again.

I've not tried reversing the polarity, I have no idea how. As I said, I know only the absolute basics of electrics.

DontFallTim wrote: I can't get to the bike right now, so I'll correct this tomorrow if I'm wrong, but no, the rear brake never turned on the brake light and still doesn't.

Hmm. Okay. I was looking for a way to ensure that the brake light is still good. Have you checked the bulb and the rest of the connections?

I don't think the old perch will receive the wires as they are. The cylinder was replaced a couple weeks ago. Pretty sure my buddy and I lost the connector in the rush (clipped the old connector off when we saw the new perch used a different type) to get the front brake working again.

Okay.

I've not tried reversing the polarity, I have no idea how. As I said, I know only the absolute basics of electrics.

It was kind of a dumb Star Trek joke, but the real question was how do you know the wires were connected correctly? Did the new perch come with instructions and/or do you have a wiring diagram for your bike? If you guys took a guess at the wires it's possible you just have them on the wrong terminals and need to swap them around. I believe one should be hot (12v) coming into the switch and the other one leaving the switch should only be hot when the brake light is on.

Likely a brown wire from harness providing battery+ to the front brake switch and a blue wire from the front brake switch that runs through the wiring harness to the brake light bulb filament.

When front brake is applied, the switch should operate to connect the brown to blue whereby battery+ is furnished to the brake light bulb filament.

The rear brake switch works the same way.

There's probably a bullet connector under the seat where the blue wire from the harness connects to a blue wire into the rear light.

Both rear bulb filaments (tail light and brake light) are grounded via the same black/yellow wire that probably connects via a bullet connector to a black/yellow wire from the harness.

Would also assure that the rear bulb brake filament isn't blown.
Can usually see a blown filament by looking closely at the bulb.

Is the dash-board brake light indicator blinking while just riding along without any brake application?

Good Fortune!

[Note to loudhvx -- please feel at liberty to adopt and freely use this marvelous diagram.]


Good Fortune!

Im sure you realaize that the front brake light is the reverse of the rear. The rear switch needs pulled to activate,the front switch needs pulled. Meaning that if the front switch is not connected to the leaver, the brake light is constantly on.
(Took me a while to figure it out, then it made sense).
Maybe this helps.

Davido:

Really? Excellent. I was just about to report I have a single bulb unit and so far nothing has worked. I'll check that out tonight.

Thanks for the help so far, guys. I'll do some more digging around my bike. So far the cables are connected to the new perch/lever, and both the stop lamp indicator on the dash and the stop light is on. I thought I fixed it but I only confused one problem with another and once that was sorted, this is back where I am. I'll check the grounds and whatnot next, because as far as the perch end of the bike is concerned, the circuit is complete.

I figured it out:

When I replaced my master cylinder and perch, the switch I swapped out is not the OEM style. As far as I can tell, OEM KZ650 switches break the circuit, turning the stop light on when pressed. This switch completes the circuit when pressed, I think. So when I touch the brake wires to bars, they spark, so they're live, too, if that helps. I need to find a compatible switch to plug into my two-prong master cylinder, but I can't find any so far. Can Z1 help, or anybody know of good ones from EBay?

Perhaps one of these

www.z1enterprises.com/product/KS12-0010

www.z1enterprises.com/product/KS12-0011

www.z1enterprises.com/product/KS12-0012

www.z1enterprises.com/product/KS12-0013

Good Fortune!

Thanks, Patton. Those won't fit my master cylinder, or I don't understand enough. I picked up this cylinder/perch:
www.amazon.com/gp/aw/d/B00D0MSX36/
All because I accidentally killed the expanding rubber thing in my OEM mc reservoir. At this point, I think I've lost a few things needed to make that old reservoir work, like the plug-style (not threaded) switch for the perch, and a number of other bits.

Questions (I'm really new to this, so assume I'm an idiot for this):
How would I use the switches Patton linked on the mc/perch I linked in this post?
If those can't be used, what type of plug or switch am I looking for to work with my linked mc/perch?

My understanding so far is this: the new mc/perch I bought probably isn't compatible with my bike, as I think the switch works opposite of the OEM switch. Currently my brake light is always on, as my dash and the light itself indicate. I need a switch that only turns it on when pressed, which should mean a switch that is off-on, not on-off, yeah? (Kills the circuit by default, allows the circuit otherwise.) To make this switch work, do I need to ground something in particular or pick up an additional part?

Apologies if some of this has already been explained and I simply haven't understood it. I've been really frustrated with the speedo somehow not working (that's another story, still diagnosing but think it's the gauge) and this last electrical hiccup holding this bike back from inspection. And I suck at electrical.