2009 R1200RT Electrical Issue

[pffog]

How exactly would that happen?

The ZFE doesn't control the current draw (aside from it cutting it off if it sees really excessive draw - ie - a short circuit..) - If you hook the same bulb up across the battery - it will light up just fine, and draw the current calculated by Ohms law. The battery is capable of supplying lots of current, way more then the bulb will draw.

The reason for the bulb blowing when the voltage exceeds the correct value IS excessive current - but that current happens because of Ohms law.. without the increase in voltage, the current draw of the bulb will remain the same.

http://www.the12volt.com/ohm/ohmslaw.asp

http://www.the12volt.com/ohm/ohmslawcalculators.asp <-- a very useful website for calculating the size of the fuses you should be installing in your auxiliary circuits..

What he said, the ONLY way to get more current through a bulb is to increase the voltage. Yes in a series circuit if you short one of the bulbs, the other will get MORE voltage, and pass more current, but Christmas lights are about the only common use of series lights. Vehicle lights are NOT generally in series.

I vote voltage regulator too. The only other thing I have seen is an intermittent battery connection, that lets the voltage surge, before the regulator can react.

An alternator by itself can produce very high voltage if not "throttled" by the regulator, or not buffered by battery capacity.

 

[hjsbmw]

BUT - the bulbs aren't connected with a resistor. They are rated for 12.6V (ie - battery voltage). I still fail to see any way this could happen.

Frankly, me neither without seeing the bike and the add-ons it had installed. Just take what I said as food for thought and not too serious other than that. I haven't designed the electronics.