Welcome to Netrider ... Connecting Riders!

Interested in talking motorbikes with a terrific community of riders?
Signup (it's quick and free) to join the discussions and access the full suite of tools and information that Netrider has to offer.

Electrical gremlin Gs500

Discussion in 'Technical and Troubleshooting Torque' started by knight76, May 29, 2013.

  1. #1 knight76, May 29, 2013
    Last edited: May 29, 2013
    Hi all.

    My Gs500 has been working without fault for a long time and just recently has developed an issue. I use the bike daily to and from work it's a real workhorse. After going through a roundabout and going to accelerate the bike died in throttle response, and the bike was running rough, not like starving fuel, but more electrically, like spark issue.

    I pulled over and the bike died, re-started and was able to keep it going with the choke on full. That got me the rest of the way to work which was only 1km or so further. Though I was seeing strange electrical behavior like when turning the headlight on all the lights on the dash would blink erratically. And it did loose power momentarily again during that 1km.

    Another factor is it was raining on that day, not really heavy, but steady.

    When I parked it at work I tried to re-start it and it was dead, no power to anything. Starter fuse had blown.

    Later that day I replaced it, bike started again fine and blew the fuse again when I hit the brake. I blew a few more fuses diagnosing it in my lunch breaks that day and the next, and what I found was if the engine was running, hitting the brake, front or rear, would blow the fuse. With the ignition on but the kill switch off, the brake could be pressed and it would be fine.

    It was also fine just to sit there idling away, or hitting high/low beam, blinkers, horn etc all fine.

    I disconnected the rear brake light housing in case there was an issue with the brake light unit or the wiring back there. My thinking was both front and rear brakes blow fuse so this is the common factor. It still blew the fuse.

    As it was only blowing the fuse when the bike was running I managed to ride it home later of a night with virtually no traffic on the roads, I only had to brake once on the trip and just kill switched it prior to braking.

    The next day was a day off for me, so I set about hunting down any wiring issues. But, I was now able to run the bike without issue. Hit the brakes and it was fine.

    I still took all the fairing off, seat and petrol tank and had a good look. There was only 1 small spot of wear on the main wiring harness where it is pressed against the chassis. It had rubbed through the black tape wrapping and I could see the colored insulated wires beneath. Only very slightly mind you and a quick glance you would think it was just a bit rubbed but not through. A close look and it was just rubbed enough through in two 1-2mm spots. They were a bit dirty in there but I think, there is a slight nick in the insulation on one wire, only very small though, but again, enough that I think it was exposing the wiring. The exposed wiring section would be very small, like 1/2 mm or so. I sparky taped this up very thoroughly and zip tied the sparky tape so it won't undo in a hurry.

    My thinking is in the rain, the water would reach the point where that slight nick was in the main wiring harness causing a short against the frame and cause the above issues. But that is just a guess and after a day of mucking around with the bike, I am just hopeful this is the fault. And probably won't know until the next decent rain I ride in.

    So, anyone experienced similar symptoms?

    Hitting brakes with bike on blows fuse.
    Kill switch active and no fuse blown even with ignition on.
  2. Test your regulator.
  3. Blinking lights and other strange electrical goings on sounds like classic earth problems to me. Have you checked your earth leads to the chassis and engine block?
  4. Thanks for the suggestions, I'm going to check these on the weekend, though I checked the earth points and they looked fine to me. I'll get the multimeter out and check the regulator.

    It made it to work and back today at least.
  5. Before you wrote about the worn section, I was going to suggest looking for something like that.

    I'm betting your problem is fixed