The MoCo manual was no help with troubleshooting this, and little/nothing from the search function. Problem: I have no brake light.

I have read somewhere that the brake light (lamp) isn't supposed to go on when using only the front brakes. Not sure if it lights by using only the rears, or both brakes must be used to light it. Anyway, I have no light in any case. I have also read that there is a brake lamp fuse, but I don't think there was a fuse for my model year - '92 1200XL - only a circuit breaker, which is...? Under the seat? And if so , what does it look like?

I have an aftermarket plate holder with integral LED running/brake light mounted to my left frame tail near the axle nut. It lights up like it should with the ignition on.

It's also possible that the brake light is stuck on - without any other light choices, I can't tell how bright either running or brake light is supposed to be. So maybe I'm looking at the brake light after all and it won't go off for some reason.

For the record, I recently replaced my front brake switch in the throttle housing. I can't swear if I had brake lights before that or not. Maybe I F'ed that up.

So where do I look? What do I check? TIA.

 

Try un hooking the led and then see if the brake light works. If not, my guess would be it's in the wiring somewhere

 

I would say that's the first place to look.

 

That prob would be the best place to start

 

If you didn't use a load equalizer, then I'd think the above answer should help you. It should help either way, because if it's a switch problem, you'd know.


This is going to sound dumb, but it's not meant to be. Have you checked the bulb? I am guessing you still have a stock fender mounted brake light, PLUS the LED one, right?

What year are you dealing with? Got pics?

Also, your brake light should be on no matter if you use the front or rear brake.

 

Service manual has a schematic.

Otherwise - remove the lens, remove the bulb. Turn your lights on. With a meter set to measure at least 12VDC, touch the positive probe to one of the pins that contacts the bulb, and the negative probe to a good ground. If you get 12VDC you've found the tail light connector. Move the positive probe to the other pin in the socket. Have someone operate the rear brake. You should see 12VDC again. If not follow the brake line from the master cylinder towards the caliper. Somewhere along the way you'll find the pressure switch. Use a short piece of wire or a pair of needlenose pliers or something to short across the connectors on the pressure switch. With the meter connected to that brake pin, you should see 12VDC. If you do, the pressure switch is bad. If you don't, "unshort" your pressure switch and connect the positive meter lead to one of the switch connectors. Leave the negative probe hooked to ground. You might have to try both pressure switch connections, but one of them should show 12VDC. If neither do, the problem might be in the wiring, or the circuit breaker. Usually though, the breaker that feeds the stop lights also feeds turn signals, too.

 

Thanks for the tips so far.

I guess I wasn't clear enough: the LED license plate holder/taillight is also the only rear brake light - there's no other rear light (though I do have functioning rear turn signals, which are on with ignition). If the breaker that runs the turn signals also runs the brake light, then I'm golden with the breaker. I'll look deeper into the front brake lamp switch.

You're sure the front brakes alone should illuminate the brake light? There's no fuse to look at or replace?

 

the front and rear brakes each have their OWN brake light switches, each brake if used on its own will light up the light, as well as both being used at the same time.


a mechanic at a dealer told me that the front brake switches often have problems and instead of replacing a bad design they cut it out and tell the customer to use the rear to activate the brake light. terrible practice and excuse for laziness, he says theve been doing it for years and i see it on some older sporties i work on.

hope that didnt happen to you, or at least you had more knowledge of it. but your bike is not wired correctly.

 

Okay, update...

First of all, the brake switch in the throttle housing is working properly. Check.

Second, I found some sh!tty wiring under the seat leading to the rear blinkers from the multi-plug. New pins will be going in.

And third, the brake light is stuck on. There are two wires going to the taillight - red and green - which do both running light and brake light. Red - running, green - brakes, as far as I can tell.

So I follow the green wire up to the plug under the seat, where it changes to blue and runs inside the wire harness under the tank. ****.

Second brake issue (and probably the main problem): the brake pressure switch is broken. The red lead is completely off the switch pin. This red lead is hot when the front brakes are applied, and apparently sending brake light love through the pressure switch to the (other) orange wire. Which goes... where?

I can follow a schematic, but they don't show where the damn modules are located on the frame. Any of you wiring gurus have some suggestions? Is it your opinion that the brake fluid pressure switch (which is disconnected for all intents and purposes) is the culprit? The brake light is on no matter what the pressure switch is connected or not (I jumped it - no response).

TIA again.

Gary

 

the hot wire runs from the electrical source, THROUGH whatever switches are needed, than into the bulb, and from the bulb it is grounded. everything is grounded to the frame. sometimes the bulb housing itself is grounded and you will ONLY see hot wires going into the casing.

you have to determine if

A. both filaments (tail light AND brake light) are constantly on.

or b. if the tail light and brake light wires have been switched somewhere becuase the two filaments in the bulb are NOT equal, one is dim and one is bright, the dim stays on constantly as the tail light and the bright comes on for the brake light

the pressure switch in the rear brake is located underneath the battery tray. try hooking the two wires from it into a seperate switch, and then turn that switch on and off to see if its a faulty pressure switch.

your profile says your in socal, i can come by and help you take a real good look at the whole system, i know how they run and where everything is. send me a PM if your interested, im free all weekend