2013 VSTROM 650, 31,000 miles. I have a LED voltage monitor that shows different colors for system voltage. Today it turned red twice for a few seconds. I went home and checked voltage with a multimeter and got 13.8 running. I strapped the meter to the handlebars and went for a test ride. During the first few miles the voltage varied rapidly from 13.2 to 13.8. The light did not come on again. My Haynes book says to check connections under the air box. Since the problem is not constant, I hope to find a loose or corroded connection. Anything else I can check?