I can't seem to get the r's headlight to work. Putting the voltmeter on the headlight plug with the engine idling yields around 4V. I thought it maybe was the regulator, but I put a new one on and it didn't change anything. Anyone got any ideas?

 

The regulator only holds the current to 12-12.5 volts. At idle 4 volts may be normal depending on the stator, however without the regulator it may produce 50 volts at WOT. Mine popped 100 watt bulbs at 5000 rpms, without a regulator. I would check connections, starting at the headlight and working to the stator or vice-versa. Maybe it's something simple like a bad bulb connection or loose socket wiring.

 

That's where I'm at. I plugged the light to a 12V battery and it works, so now I am in process of going back and checking continuity. I hate electrical problems, can't see those pesky electrons.