short circuit with yamaha XC180 scooter

[justforfun]

I turn the key from Off to On and nothing happens. The lights should come on and the lcd speedometer should light up.

It did actually come on once for no apparent reason while I was checking it out. Once it came on, it started fine and I rode it around for about 20 minutes before it died again.

This and my multimeter tests rule out starter, battery, and fuses as potential sources of the problem. The battery is 8 months old. It has to be a short somewhere.

I picked up a service manual and verified continuity between the battery and the main switch, and verified operation of the switch.

All the connectors appear to be tight and I don't see any chafed wires.

Are there any systematic approaches to locating a short? The battery is not draining. Does this fact rule out a short to ground, leaving only an open circuit possibility?

thanks!

[Sev]

Test the ignition switch, wires leading too it, and the starter button.

[justforfun]

Thanks. I will check that out tomorrow. I'm calling it a day for now.

In my latest tinkering, I measured 12V between the positive battery terminal and the red lead input connection to the main switch. I thought that voltage should be zero. No?

[Tazman1296]

Some high current demands warranted from a starter cannot pass thru the starter switch and that switch may be wired thru a relay. Check to see if one exists and that may be hanging up... Hope that helps !

[Evil Twin Brother]

I would check all frame ground connections, also check connectors for corrosion. Try turning the key on and wiggle your wiring harness around.
I would find all of your frame grounds, then clean and tighten them.