Brake light does not work when front or rear brake pressed

[PassTheRock]

Hi all. New to the forum. I'm also a new rider and owner of a 250. I've got a problem. My front and rear brakes do not activate my brake light. Here's a rough timeline:

I got my 250 about a month ago. The front brake lever activated the brake light, but the rear brake did not activate it.
Taillight always worked, but then front brake activation stopped activating brake light.
I let it sit overnight, and it worked for a time until this week.
This week, taillight did not even work.
I fixed the taillight by replacing the fuse for the taillight (it blew), but brake lights did not activate.
I checked wires and connections and everything seems to be fine. There's an audible click when the front brake lever is pressed so I believe that is okay.

In my humble opinion, I believe it is either the electrical connection between by front and rear break switch as shown in the wiring diagram or a bad ground. My question is how do I know where to look on the bike and try to narrow it down? Do I even seem like I am on the right track? Thanks in advance!

[csmith12]

Welcome!

First thing I would check is the bulb and good luck!

[CaliGrrl]

Welcome! I'd check the bulb, too, and the activation switch. I need to get into my tail lights and replace a lamp.

[adouglas]

Certainly seems as if one of the issues could be a busted filament in the bulb (there are two... one tail, one brake, so you can get a working tail light with no brake light).

But the other symptoms, especially the blown fuse, suggest short or ground issue. You have to trace the wires. Since the fuse blew, most likely downstream from there. Since the wires are wrapped up in bundles and therefore protected from the elements, start with the stuff you can see and stuff that can get corroded (e.g., connectors).

If you get well and truly stuck, engage in troubleshooting 101... isolate every piece of the circuit one by one and verify that it works (i.e., if you unplug the tail light assembly, apply voltage across the terminals and the bulb filaments light up, you've eliminated the bulb and the fixture... if you unplug the brake lever switch, rig up a test light an the switch activates the light, then the switch is okay... and so on).

[jkv45]

I would start with a new bulb (get 2) and see what happens. I would also look at the wires coming from the taillight to see if the insulation has been worn off, which would cause the fuse to blow. Something made it blow, so you should look for the cause.

For the brake light, if it's still not working, I would use a test light, get the levers to stay in the "on" position somehow, and start tracing the power into and out of the switch and back to the socket.

Confirm you have power into the switch and out of the switch when "on", then find where it stops if you don't have it at the socket.

[PassTheRock]

Originally Posted by adouglas

Certainly seems as if one of the issues could be a busted filament in the bulb (there are two... one tail, one brake, so you can get a working tail light with no brake light).

But the other symptoms, especially the blown fuse, suggest short or ground issue. You have to trace the wires. Since the fuse blew, most likely downstream from there. Since the wires are wrapped up in bundles and therefore protected from the elements, start with the stuff you can see and stuff that can get corroded (e.g., connectors).

Because I'm new, I don't know if it's stock or not. But the previous owner removed the rear turn signals and rigged the turn signal lights to shine on the taillight. I'll take the taillight apart when I get home later, but my taillight also includes my brake light and turn signals.

Also, I forgot to mention but this could be important, even when my taillight was not working, the turn signals still worked when toggled.

Here is a picture of my taillight, to avoid any confusion:

https://imgur.com/a/cDO1Y

[adouglas]

Yeah, aftermarket, with LEDs not a bulb.

Likely a half-assed wiring job. Betcha there will be loose/missing electrical tape in there somewhere, wires twisted together but not soldered, etc.

Pull the tail light, verify function by applying voltage at the appropriate points, and reinstall properly.

[PassTheRock]

Originally Posted by adouglas

Likely a half-assed wiring job. Betcha there will be loose/missing electrical tape in there somewhere, wires twisted together but not soldered, etc.

I took note yesterday of wires leaving my rear brake switch (or what I believe is the switch). They are pretty heavily pinched between the frame and something else. A couple inches away from there is a wire nut. I'll investigate this and update later.

[NevadaWolf]

That's an integrated taillight (meaning the turn signals, brake, and tail are all in the same housing). As mentioned, not stock.

There will be multiple wires coming out of the back of it. The (likely) yellow wires are for your turn signals. The remaining three (likely red, green, and black) are the positive and ground for the tail and brake. On mine, the three wires were loose and I had to connect them to the wiring harness myself. But I'm seeing versions online with plug n' play connections for the brake/tail.

Originally Posted by PassTheRock

I took note yesterday of wires leaving my rear brake switch (or what I believe is the switch). They are pretty heavily pinched between the frame and something else. A couple inches away from there is a wire nut. I'll investigate this and update later.

I suspect the problem is at the light, not at the switch. Since it's aftermarket, there's a better chance of failure from the install there than a chance of failure with factory wiring. Eliminate the easy end first.

[Triple Jim]

Originally Posted by PassTheRock

A couple inches away from there is a wire nut.

Wire nuts are in the same category as taped twisted wires. The installer didn't take the time to do the job properly. You can use wire nuts to get it working long enough to verify everything is correct, but then redo all the connections with solder and heat shrink tubing.

[jkv45]

Originally Posted by PassTheRock

I took note yesterday of wires leaving my rear brake switch (or what I believe is the switch). They are pretty heavily pinched between the frame and something else. A couple inches away from there is a wire nut. I'll investigate this and update later.

A telltale sign of rookie wiring right there.

[PassTheRock]

Here's an update from me that's got me stumped.

I took my multimeter and went to work. Seeing as how I saw nothing obvious regarding exposed copper or whatnot, I investigated the BL/R common connection that the Brake Light and Brake Switches share. In performing a continuity test, I verified that the connection between the Front Brake Switch and the Taillight exists. However, with the battery active, I voltage tested both of these connections. I got a voltage reading for this wire on the Front Brake Switch connector, but not at the taillight connector. How could this be?

EDIT: Disregard the underlined portion. I confused myself with the R/BL wire. So, my BL/R does not have voltage on it, but nothing obvious appears to me where I'm losing that connection.

EDIT 2: This just occurred to me, do I have to actuate one of the switches to get a voltage reading on that BL/R wire with the battery active?

[jkv45]

Originally Posted by PassTheRock

Here's an update from me that's got me stumped.

(SNIP)

EDIT 2: This just occurred to me, do I have to actuate one of the switches to get a voltage reading on that BL/R wire with the battery active?

If I'm following your question correctly - yes.

Test for power coming into and out of the switch with it is activated. Use tape or a rubber band on the front brake lever to hold it "on", and find something for the rear brake lever that will do the same, then follow the power towards the light.

[Ralgha]

Soldering isn't the best way on vehicles because the joint is rigid and will get stressed by the everyday vibrations and movement of the vehicle. Depending on the situation, you may not be able to avoid it, but you can always avoid it for connecting wires together.

Use crimped connectors and a proper crimping tool, no solder. You can simply use a butt splice to get a permanent connection, bullet connectors for a generic disconnectable one, or use OEM connectors.

[Triple Jim]

There's always the too-stiff argument, and the counter-argument is that most crimp connectors allow moisture in, and eventually corrosion happens. I've had to repair several original factory crimp connections on my '72 Kawasaki. But if you solder and use heat shrink tubing over the joint, there won't be enough bending to ever crack anything.

[jkv45]

Originally Posted by Ralgha

Soldering isn't the best way on vehicles because the joint is rigid and will get stressed by the everyday vibrations and movement of the vehicle. Depending on the situation, you may not be able to avoid it, but you can always avoid it for connecting wires together.

Use crimped connectors and a proper crimping tool, no solder. You can simply use a butt splice to get a permanent connection, bullet connectors for a generic disconnectable one, or use OEM connectors.

If you do go the crimp route (sometimes you need to be able to unfasten the connection to remove a part), a little bit of Dielectric Grease (EDIT: that may not be the best choice, as suggested by TJ below) on the connection is a good idea. It seals the connection and provides some amount of corrosion protection while making it easier to remove later.

I've used heat shrink over (smaller round) crimp connections before if I though they needed additional protection from moisture.

[Triple Jim]

Dielectric grease is designed to prevent electrical current flow. You're much better off with something like Penetrox, which is made to help conductivity and prevent corrosion in electrical joints.

[DannoXYZ]

Crimped connection is even more rigid than soldering. At least with soldering it is smooth transition. A crimp has sudden change in diameter and rigidity, leading to a stress riser that'll break wire at spot where it entre crimp.

[jkv45]

Originally Posted by Triple Jim

Dielectric grease is designed to prevent electrical current flow. You're much better off with something like Penetrox, which is made to help conductivity and prevent corrosion in electrical joints.

There seems to be some debate on whether it's a good idea to use on connectors or not, but I would say you are right to use a conductive product instead.

They say that the grease is removed from the actual contact area by friction when the connector is made, but seals it from moisture. I have used it for years without any problems, but that doesn't make it right...

[DannoXYZ]

Mil-spec, aerospace and Formulae-1 uses crimped and soldered connections. The crimped terminals provides chanical strength. Solder provides electrical conductivity, seals wire-ends from black/green wire-disease and gives smooth transition from flexible to rigid joint for lower stress-risers.

[Triple Jim]

You're right, it squeezes out and allows contact, but it's really made for things like high voltage connectors, to prevent arcing between the wire and connector housing, for example. Like on spark plug boots.

Burndy makes several versions of Penetrox for a range of connection types including aluminum wire to copper connectors. The one for copper on copper is the one to have a squeeze bottle of in your tool box. One of the larger sizes is a lifetime supply. I got mine back in the '80s and it's still mostly full.

[PassTheRock]

Originally Posted by jkv45

If I'm following your question correctly - yes.

Test for power coming into and out of the switch with it is activated. Use tape or a rubber band on the front brake lever to hold it "on", and find something for the rear brake lever that will do the same, then follow the power towards the light.

I believe I fixed the issue. The Red wire leading into the License Plate light was frayed, so I patched it with electrical tape and it seems to be working. I guess from looking at the electrical diagram, it wasn't apparent to me that a frayed wire for the license plate light would cause the brake light not to work. I will check before each ride.

Now, in loo of using screws, the previous owner used zip-ties to secure alot of stuff. Is there a spec sheet somewhere that calls out screw sizes for the fairings, seat, and back compartment?

Thank you all for your help!

[DannoXYZ]

Most screws are 5 or 6mm. I just got bag of alloy allen socket-head screws in various sizes and replaced all of them on my race-bike and now I've got tonne of spares.

http://www.ebay.com/itm/282556865931

[DannoXYZ]

Good job tracking that down!

Originally Posted by PassTheRock

I believe I fixed the issue. The Red wire leading into the License Plate light was frayed, so I patched it with electrical tape and it seems to be working. I guess from looking at the electrical diagram, it wasn't apparent to me that a frayed wire for the license plate light would cause the brake light not to work. I will check before each ride.

Both the licence-plate and brake lights use teh same red/blue +12v supply wire from the ignition-switch. With short and blown-fuse, both would not work. Even if fuse not blown, short would suck up all power and neither licence or brake lights will work.

Personally, I would cut through exposed section of wire, slide over heat-shrink wrap, solder wire-ends back together and seal with heat-shrink. Fix it once and fix it permanently.

Link to original page on YouTube.