Brake light problem.

The brake light on my 08 SM450 stopped working. The tail light still works though. Anyone know which fuse controls this? Or what the problem might be?

Don't know the system on your bike at all but likely problem areas are: brake light bulb, brake switch, or wiring. Could possibly be a fuse, but I've not often seen bikes with a separate fuse just for the brake light circuit - normally if a fuse went you'd lose other stuff too so if nothing else has failed it's unlikely to be a fuse unless you have a panel with lots of fuses on it!

If it was working for both front and rear brakes and then suddenly stopped working for either at the same point it's probably not the brake switches as there is one for each brake and it's unlikely they'd both fail simultaneously.

If the brake light is a normal bulb (rather than LEDs) you can usually see whether the filament is ok if you take the bulb out (if you shake it gently you may hear the broken filament rattling), or if you're not sure just replace the bulb and see if that fixes the problem as it's easily the most likely cause. It may be a combined single tail and stop bulb in which case it will have two filaments and it's possible for the brake filament to fail while the tail light filament is ok so it could still be the bulb that's the problem even though the tail light is working. If you have separate tail and stop bulbs then check out the stop light bulb and replace that if necessary.

If it's not the bulb or the switches, then you may either have a broken wire or a connector has come off somewhere (it could be an earthing problem but that would probably kill the stop light too). The easiest cabling to check will be that closest to the tail light assembly as you'll at least know that's all related to the tail or stop light. See if anything's loose or broken. If you have to trace further back where the wires get mixed in with other circuits it will get trickier to see them and it would be easier to have someone with a voltmeter do some testing.

Is the light brighter than normal as if you were braking? I had that happen on the 510 and it ended up being that the brake lever wasn't pushing the little button in that causes the brake light to go off. When the lever is all the way out, it pushes a button in. I think mine had just gotten misaligned so it was on all the time. You might check that.

And dirtdame is right about those bulbs. I ended up replacing my taillight with LED because I went through like 3 bulbs in two weeks.

I should have mentioned its an led tail light. Its the one that comes with the power up kit on the 08's. So there is no burnt out bulb. The leds just get brighter when the brake is put on. I'll check the lever to see if the button is sticking. It doesn't seem brighter than normal though.

So ignore all my nonsense about bulbs then!

As well as checking for a sticking switch, try both brakes (front and rear) one at a time.

If the stop light works for one and not the other it's probably a brake switch or wiring problem on the failed one. The switch could be broken, disconnected, or badly adjusted so it doesn't quite make contact when you use the brake.

If it doesn't work for either brake, your problem is more likely in the wiring, possibly somewhere towards the tail light unit so check for breakages or loose connectors.

It could be the LED unit itself but they're usually quite expensive to replace (unlike a bulb) so getting a new one would be a last resort unless you're sure it's broken. If you can borrow another one you could hook it up temporarily just to see whether that's the problem. Failing that you may need someone with a multi-meter to see exactly what's happening.

One other thought: from what you said it sounds like there was a different tail light unit pre power-up (perhaps one with bulbs?). If there was and you have it, I assume the connectors would be the same as on the LED one so you could try connecting the old unit temporarily to see whether the brake light then works.

I found it. It was the front brake switch. It was comming loose and not making contact. I pushed it back in and its all good now. Thanks everyone.

Mine does that all the time too, almost every ride. Need a dab of epoxy or something to keep the switch in place.