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tail lights work, brake lights don't - VFR800

Discussion in 'Technical and Troubleshooting Torque' started by Paragon, Jan 14, 2013.

  1. Hi,

    As background I have an 04 VFR800. A few days ago I replaced the battery, which was just about dead, with a Yuasa. Now today I go and check my lights before I ride.

    The tail light works but the brake lights won't come on using either the front or rear brake.

    I have checked the fuses and they are all ok. The indicators work, horn etc....no other electrical problems or gremlins.

    I have checked and even replaced the bulbs but the same thing happens so it is not the bulbs.

    I have had a look at the wiring and can't see anything that 'stands out' as a problem, i.e. broken wires etc.

    I am assuming it has something to do with changing the battery over? The fact that neither foot or front brake will operate the lights means that it's a problem near the rear lights? I'm not much of an electrician unfortunately.

    Anyone had a similar problem and have some solution. Would be greatly appreciated as I'm now without transport until I fix it or I'll have to take it into the shop....

    Cheers in advance.
  2. Are you sure you have put in dual filament bulbs?
    Otherwise it will be the other wire(s) that switch on the brake light, it is more than two per light so it can switch between brake off/on.
    It also couldn't hurt to undo the plugs, blow them out with some compressed air and put a dab of dielectric grease in each.
  3. Oh yeah, and obv check the front and rear brake switches with a multimeter, and their connections.
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  4. +1 to Kernel check you have the right globes. Assuming that is Ok Multimeter is your next check.

    One suspicion is that you have a Regulator fault, common with Hondas, and the charge voltage is getting up very high. This would kill a battery so may be the cause of your recent battery failure. Also a side effect is that the filaments in globes blow. This is a low likelihood at the moment because of the fact your new globes did not light up at all. Something to keep in mind though.
  5. On average I have replaced the front brake switch every year on my ST1100. The little spring in the switch doesn't seem to be up to the task.

    I've never had a problem with the rear switch but I have adjusted it to come on a little earlier.
  6. Your bike has linked brakes,sounds like the connection to the common switch
  7. Ok thanks for the info . I had another look and it seems that it may be a case of the brake lights being permanently 'on' now, so it's a similar problem. I guess in that either the brake light's not working or it's permanently on . I'll check tonight Either way something is fried! I'll have to get to this switch thingy and see if it's blown? I wonder if the new battery has overloaded the system. Oh well no easy fix I'll have to take off the fairing at the back and work from there. This switch thing, what is it exactly? And the bulbs are dual filament as well, I checked.
  8. It seems a bit suss that both rear and front brake now won't operate the brake light though?
  9. Linked brakes,you know that,yes
  10. Loot is correct
  11. Th
    yes that's right. I've always been happy doing the basic servicing mechanically etc but have never really ventured into wiring etc so I'm pretty clueless ! Okay I'll have a look for this common switch to the brake light ...
  12. I have had a VFR previously, there is a separate switch for the front and rear brake.

    I vote for Reg/Rec overcharge and fried wire somewhere.

    Q, is the licence plate lamp on when the ignition is on??
  13. Yes the licence plate light works, indicators work and every other electrical thing seems ok as well. I'm assuming that when it's just the normal tail light that one filament lights up and that when the brake light is activated the other filament comes on as well. If that's the case then the brake light is now on all the time
  14. time to check those switches then (attachment) Brake switches.JPG
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  15. I found that my rear brake light switch wouldn't activate under normal braking so so I adjusted the switch 'til it did.

    It's possible it's a similar issue
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  16. If i's permanently on, check the sensor spring on the rear brake (behind the right heel shield).
    Mine had the same issue and it turned out to be and over tightened sensor spring (the have a tightening nut in there) as a consequence of me removing the shield to replace the cam chain tensioner.
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  17. try to disconnect the front switch and connect the wires the lights should come on constantly(you shouldn't start the bike, just ignition on), if so the the switch is faulty. Should be a cheap fix around $15
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  18. Solution! :) . It was the rear brake spring connected to the sensor attached to the brake pedal. Seems like a bit of gunk had accumulated and the spring was being affected. I just wound off the adjuster on the spring a few turns and now everything is back to normal!

    Thanks to everyone who posted. It was only by brainstorming it a bit and looking at all the issues that I finally worked it out (even if it was a pretty simple fix in the end).

    Looks like the new battery had nothing to do with the issue at all! I had fixated on that and thought it was an electrical issue requiring an expensive fix. Without Netrider I would probably have all the fairings off checking the wiring all day! Now I can go for a ride instead!

    I think it's only fair considering the money and time I've just saved to hand over my $10 for premium membership!

    Thanks again....
    • Like Like x 2
  19. I knew it would be something like that, it almost always is.
    • Like Like x 1