my bike was fine, rode it to a friends place, went to start it, and all the lights etc clicked off and wont come back on. the battery is ok, all fuses are ok. when i measure the voltage on the battery is 12.4v , when i turn on the ignition it goes to 0v. continuity test shows the positive wire is shorted with ground when the ignition is switched on, but not when off. bike is completely dead, what can i do/check?? please help me.