Brake light not working :(

[zaptoman]

Just bought a bandit 400 at the beginning of Feb, and I notice now that the brake light doesn't work. So I went down to NAPA and bought some 1157 bulbs (apparently these aren't the right kind anyway?) and proceeded to take the lens cover off. Turns out both filaments on the old bulb are fine. Brake light doesn't light from either the front or rear brake levers. Any suggestions?

[Krautwagen]

Are you sure there's no voltage back there?  Filaments can be curnt out and 'look' fine...


Can you hear an audible click from either lever when you press them?  Does the headlight work (IIRC, all lights run off the same fuse)?  

Check resistance from the 'side' bulb connection to the neg batt terminal.
Check continuity from lever switches to the 'center' bulb terminals.

[zaptoman]

I don't hear any sort or 'relay' type click ( like from the turn signals) from either lever. I do hear a regular clicking kind of noise that sounds to come from the lever itself. Also all the other lights work.

[PitterB4]

I'd still spend the couple bucks for a new bulb.  I'd hate to do a bunch of diagnostics to find out its a simple bulb.

[zaptoman]

I did buy a pack of 1157 dual filament bulbs. Just put one in, same symptoms. I also sprayed some wd-40 in there- no go.

[duane]

This meter is a standard with touring motorcyclists.  It's small enough to pack away and can trouble shoot problems like yours in a snap.   (Like, do you have voltage at the socket, is the bulb good, do you have voltage at the fuse block etc etc...)

WD 40 in you electrical connections?  I guess, but it will attract dirt.  Get some real electrical cleaner from Shucks, Autozone, or Radio Shack and clean it with that.

[Red01]

WD 40 in you electrical connections?  I guess, but it will attract dirt.  Get some real electrical cleaner from Shucks, Autozone, or Radio Shack and clean it with that.

Once clean, you can improve conductivity with dielectric grease, available from those same sources.

It is possible both your brake light switches are giving you problems. Check the connections and operation of the switches at each master cylinder with a meter.

[400runner]

Does the light come on when the brakes are not engaged? Meaning does the tail light work? Or is not coming on at all even when you turn the key? I ask this because the tail light has a remote cable which powers the tail all the time while the bike is on and a cable that runs to the brake levers through – I believe the neutral light- and it comes on when you engage the brakes levers. But check the wiring map( available somewhere on this site)If you do not have a meter to detect this problem you can start to isolate the issue by taking two wires and running them directly from  the source to the battery.. Disconnect the tail light ( you will have to take the tail of the bike off) Take a positive (+ tail light =Brown   + brake light = White with black stripe. )cable and a negative( solid black it’s connected to the tail housing) one and connect them to the positive and negative leads directly to the battery and see if the light comes on. Remember to check that the negative cable is connected properly and that all wires make clean contact.  If the light comes on check your fuse box which I am sure you have done. the next step is to check that your lever sensors are working properly. If the problem persist than you will have to test everything in between and that can be time consuming. I hope this helps. Also get a current tester. They cost about $5- They are the one with a positive lead, a negative and a bulb. This will tell you weather you have current running through your cables. Good luck.

[zaptoman]

Thanks guys for the help, i will update when i get it figured out.

[zaptoman]

Got it fixed! Both switches were pretty darn corroded and gunked up. Some more wd-40 cleaned em out and now the brake light is working great. Thanks for the help.

[Krautwagen]

Good job!

WD-40 should only be temporary though.  As soon (or sooner) as you notice problems, actually clean the contacts with a wire brush/electrical contact cleaner, and apply some di-electric grease to prevent any future issues.

[GooseMan]

This just started happening to mine! My taillight turns on (Well, its always on), but the brakes dont seem to do anything! Hopefully its the bulb, but I'll have to check the contacts too.

I did notice that when I start the bike, I can flash the brake light maybe 2-3 times...then it stops working...so I dunno what the problem is.

[GooseMan]

So is the correct bulb the 1157? Cause I have one at home. Is there such thing a dual-filiment bulb? My understanding is that its the same bulb....it just gets a higher wattage when the brake lights are applied.....so if the bulb works (mine is always on, but doesnt get brighter when the brakes are applied), then its a problem with the switches, and not the bulb itself....right?

I'll have to try to clean my contacts...where are they anyway?

[Red01]

1157 is a dual filament bulb... the dim filament glows for the tail light and the bright filament is activated when you step on or pull the brake lever... providing, of course, the brake switches on the levers are doing their job.

[GooseMan]

K cool.....I'll replace the bulb first....try to clean the contacts after that if it doesnt work. Hopefully that'll cure the problem. I hate electrical problems!  


DUMB question: Do I have to take apart the whole tail to replace the bulb? Or just take off the red lense with the two screws?