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No kill switch

Discussion in 'Technical and Troubleshooting Torque' started by Devery, Oct 15, 2009.

  1. Hello,

    I bought an SR250 and it runs well but it has a few problems, mainly electrical.

    The bike will run without the key in the ignition... I can disconnect the ignition switch whilst the bike is running and it will still run. The kill switch cuts power to the lights but not the ignition coil or what ever it is keeping this bike running. What should I be looking for here? All wires seem to go where they are supposed to according to the wiring diagram:

    Wiring Diagram

    Any help is appreciated, I'll answer more questions if needed.

  2. OK, somewhere, the red spotty wire in the WD is getting volts from somewhere when everything is off. Has the bike ever been stolen? Hotwiring would have that effect.

    You need to trace the red spotty wire throughout the bike and ensure that there is nothing connecting it to the red (hot at all times) wire or the big black cable from battery to starter switch.

    Also, make sure all your light globes (especially including idiot lights) and all ground connections to the bike's frame are OK. Blown globes and dodgy grounds can have some very odd effects as current finds ingenious paths back to the battery.

    If it's neither of those, you'll have to check out the switchgear. If you haven't got one, go and get a $20 multimeter with resistance (Ohms) capability from **** Smiths or Jaycar. It's a required item if you own an older bike with iffy electrics. Given the meter, you can check which switch terminals connect with which others in which position against the WD.

    However, my money would be on someone bypassing the ignition and kill switches, maybe because of a dodgy contact in one of the switches. Don't look for broken wires to start with, look for extra ones.

    Good luck.
  3. Thanks Pat. That maker sense... I'll do those checks tonight. I have a multimeter so if it comes to that I'll check all the points to make sure they are where they need to be.

    On that diagram it has the RED wire connecting to the starter switch but on my bike it connects directly to the positive terminal on the battery, could this be the problem? There are two wires connected to the battery pos terminal, the RED wire and the BLACK (from the starter switch...).

    Thanks again,

  4. Looking at the diagram, it shouldn't matter, but it does suggest that your wiring may not be as Yamaha intended it.

    Half an hour's work with a multimeter will pay dividends.
  5. Hey, I didn't get a good chance to go over the bike this weekend but maybe tonight... The other thing I thought I might include is the battery runs flat if it is left in with kill switch off and ignition turned off. Does this give hints where to look? Why is it draining the charge?

  6. Well it could be discharging via the ignition coil if the bike's been hotwired and the ignition is permanently on. Does the coil get hot when the bike's standing?
  7. I'll connect it tonight and see if it does. To hot wire it do you connect the red to the spotted red? Or is it not that simple 8-[... :)
  8. probably best for a pm reply :) We don''t want to educate the imbecilic.

    You could in the interim drop a switch at the battery you can turn on and off. $5 temporary repair. if you have trouble isolating it, or you can try and find a wiring loom on a wrecked bike at a wreckers, and replace the lot.
  9. Probably should have thought that one through, Thera. I'll be more careful next time, hehe.

    Replacing the loom might be a good idea if I can't find this damn problem... but it should come clear.

    I just found that the fuse has blown. Should the bike still start if the fuse is blown? There is power coming from the positive battery point to the starter switch which goes to the ignition coil, via the safety relay, and the kill switch. Its like the red wire isn't even in use.

    Could the starter switch be broken? or the points around the wrong way? connecting? hmm.

  10. The Fuse should kill the supply to the lot. You could possibly have a short in the starter switch(as per the diagram it is the first port of call for an always live feed off the battery) which is bypassing the fuse, or you could have a worn piece of insulation over a wire that is allowing current to pass through, or the fuse hasn't worked properly.

    Pull the fuse out and see if you have power at the switch. if you do, then it is a bigger problem than a faulty fuse.

    Or a ghost in the machine. Electrical problems are called gremlins for a reason.
  11. I think they haunt me... I will sort it out though! Thanks for your help.
  12. Fixed :D

    Thank you both for your help! Really do appreciate it.

  13. what fixed it? might be handy for someone else in the future.
  14. Well... Its basically hot wired. Without wanting to show how to hot wire my bike, there was power running to the wire that connects to the ignition coil, directly to the battery I guess...

    PM if anyone has specific questions :)