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GN250 rear brake light constantly on

Discussion in 'Technical and Troubleshooting Torque' started by Joosch, Oct 16, 2012.

  1. heya,

    first post so if this is somehow in the wrong section or something let me know.

    ill get right to the chase, i am no mechanic and everything i have looked at/for i have read on other forums through out the web, i am an IT guy so my knowledge is limited.

    my buddy bought me a 1990 GN250 for my birthday so i could learn to ride and hang with him more, it has had a few problems over the time i have had it but none that we wouldn't just google and fix, i like the bike and one day i hope to mod it up like the bobber/cafe racers i see everywhere but the current problem which has both of us stumped and i can't find a fix anywhere for is the brake light. few days ago i realised that the brake light was constantly on so i googled and there were a few reasons people said, stuck switches,bulbs, springs or the light switch.

    i had a look today and i replaced the bulb, had a look at the front brake lever and the switch on it which to me looked fine, i took the lever off and pressed the switch in but nothing happened. i looked at the springs on the back brake pedal and they looked fine to me.i also loosened the bolt so the foot pedal would sit back further and maybe turn it off but it didnt. I found the rear light switch(not sure if that's what its called?) but i have no idea what to look for and its hard to get to.

    any ideas would be great, i have no cash so i cant take it to a mechanics D:
  2. Brake light permantly on usually means that the switch has fused closed. Not uncommon with older bikes, basically the result of thin bits of metal "growing" out from one of the electrodes until they from a permanent bridge (common problem on the old morse code tappers).

    Replacement switch would be the easiest solution, and given they're a fairly common (and cheap) bike should only be 20 bucks or so for a new one. Cheaper option, if it's possible to get the switch apart without destroying it (or losing one of the tiny springs that's usually always hiding inside a switch just waiting to escape), is to just file/sand the contacts back till they're as good as new.

    Edit: Oh and well worth investing in a $10 multi-meter. Checking the change in resistance of the two switches will tell you which one is stuffed (though I'd be inclined to just fix/replace both anyway).
  3. i was playing with the switch but i can't seem to get it unplugged, i pulled on it fairly hard to try and budge it but i didn't want to fully rip on it because i didn't want to break stuff more than it already is.

    should i just get a firm grip and pull from the top? or am i not getting how it works, it looks kinda like this
  4. May be adjustment of the rear switch if you (or someone) has adjusted the rear brake lever/ pedal. If it's anything like the Across you've got to re-adjust the switch if you change the angle of dangle of the pedal. Sh1t design. It's a pain in the rrrr to do, too.

    Once again, Across case but likely similar, the switch is tied to the pedal by a springy actuating rod, adjustment is by rotating the switch body wich screws it up and down, increasing or decreasing the spring tension which pulls against the tension in the switch. It's really iffy but once you've got it right it seems to be ok.

  5. Could be a number of causes but first I would check the switch, as above
  6. i checked the switch, the spring coming off it has rusted up a fair bit and is pretty shitty the switch it self looked a bit damaged so i managed to get another one from a wreckers which is in far better shape but still no luck i can pull down on it or let it up and its always on still.

    is there something i am missing?
  7. When you disconnect the rear brake switch, does the rear brake light still stay on?
  8. yeah it does which leads me to believe that its not the switch? i replaced the bulb with a brand new one this morning too
  9. If that's the case then try disconnecting the front brake switch, and see if the light still stays on.
  10. try unplugging the front brake switch, does the front brake light stay on?

    sorry, i couldn't resist..
  11. how would i go about finding it? i followed the cables from the front lever and it goes to the disc on the front.
  12. Those would be hoses, not cables. Best to leave those alone.

    The front brake switch should be a small black box near the pivot point of your front brake lever. Should look like this:
  13. my bad i am a retard i know exactly what it is now haha
  14. took the front lever out and disconnected what i think was the switch and the light is now off and the back switch turns it on which is good but i put it all back together and the front one doesn't make it turn on, all i did was unscrew the part below the lever saw it had some gunky shit on it and wiped it off then screwed it back on.
  15. I'm guessing it's the gunky shit that was making the light stay on, and that your front brake switch is stuffed.

    Looks similar to the one I had fail on my old GSX250 in which case it is possible (though not exactly easy) to get it apart and fix it. In your case it might be easier though to just source a replacement. Welcome to the joys of old, cheap bikes. :)
  16. SUCESS! turns out i was putting in the little copper thing the wrong way when i put it back in. it had fallen over instead of being up straight i put it up straight put my lever back on and she all works!


    thank you so very much if i could send you an internet beer i would.
  17. Excellent. Now we'll just wait for the next electrical issue to raise it's head.
    Which being a Suzuki, shouldn't take too long :LOL:.
  18. Jd, your avatar is great. It's hypnotizing me.
  19. Yes I haven't decided if it is a Dinaoctoduck or a Duckopussasaurus ???
  20. Is an Oxtoduckosaurus :).