Join Date: Oct 2013
Location: Chilliwack, BC, Canada
You need to sample the Brown wire at the Headlight Fuse, not the White wire which is the battery power to the system. The White wire (and Main fuse) only samples current flow into and out of the battery so will show the total system load only while engine is not running.
With engine running, the VRR White wire provides the power to the system and this connects to the White wire at Junction #2. For this reason, current flow in the Main Fuse will be in either direction depending on whether battery is powering, or being charged, from the system.
One needs to be certain of the circuit being measured.
First thing I would question is the meter calibration.
What Wattage is the Headlight bulb? Stock is 55 or 60 Watt but many install 100 Watt which will about double the draw.
Are you able to check the current flow through the headlight bulb? What is the current flow according to your meter? That should provide a calibration indicator.
If you do have high current or any significant current in the Headlight Fuse circuit with the Headlight out, then some investigation is obviously required.
First thing in that regards is two question whether the wiring is stock?
If the harness has the Brown Wire Modification, the Headlight is not powered by the Headlight Fuse, but rather only from the Main Fuse.
I'm certain that you already know this but for someone following the thread which does not, a brief description of the powering of the headlight:
With engine not running, the bike is powered from the battery, through the Main Fuse by way of the White Wire which powers some components with key off, and powers the Ignition Switch. When engine starts (assuming sufficient RPM) the White Wire is also powered by the VRR but the effect is the same in so far as the White Wire is concerned beyond the Junction #2.
Power from the White Wire to the Ignition Switch which powers the Brown wire to the Headlight and most other components switched by the Ignition Switch. The Brown Wire powers Horn and several other components, then all the way back to the Fuses to power the Headlight Fuse then forward through the Blue/White to the Dimmer Switch.
If you would like some suggestions as to diagnosis, I'm happy to try to help.