There were some questions about confirming whether or not you are looking at the correct wires or pin location when doing this modification. For some, it can be an overwhelming ordeal to gain access to the connector because of the removal of the air box and battery box. It would be nice to get it right the first time, in case there was some doubt. After looking a the 2004, 2006, and 2007 wiring diagrams in the respective service manuals, I believe that the following information should be correct but sometimes literature or people can be wrong. Verify if you feel the need to re-assure yourself as, hey, it’s your bike, right? The 2005 service manual did not have a wiring diagram in it but going from the 2004 to 2006 showed no change so I would assume 2005 would be the same.
The simplest way to confirm that you are tapping into the right wire is turn it on, right? Since the air box and battery has been removed, that kind of eliminates this test. The only thing left that you can do is perform a resistive check with an ohm meter or DVM.
Let’s take a crash course on wiring schematics. Before we do the test, it helps to see schematically what the wire harness actually does. In the Schematic_1 taken from the 2004 service manual, I have laid a red line from the bottom of the dashed box outline (item 53) to the lower part of the wiring schematic and ending at the hi-lo bulb (item 62). That red line, or the wire harness provides a path for the (+) side of the battery to the lo-beam filament when the hi-lo beam switch (item 55) is switched to lo-beam.
Schematic_2 is a close-up shot of item 53, the female connector from the left handlebar switch assembly. Everything contained within the dashed box outline is the switch assembly. Item 55 is the hi-lo beam switch. I have drawn it electrical as something everyone should be familiar with at the bottom of this schematic. As that little drawing of mine indicates, when item 55, the hi-lo beam switch is on hi-beam, the light blue common line makes contact with the yellow line. When the switch is flipped to lo-beam, the light blue common line makes contact with the green line. Inside the dashed box, I’ve outlined in a solid red box the female connector toward the upper left. This indicates where on the connector you should expect to find these three wires that I mentioned, as they are also appropriately labeled along the black lines or wires that are leaving the dashed box line. Given now the colors of wires that you are looking for and the possible location that they can be found on the female connector, using an ohm meter you can test the continuity of the light blue to yellow for hi-beam and the light blue to green for lo-beam. In other words, you are looking for zero ohms or a short between the light blue and yellow when the switch is in hi-beam while an open or infinite ohms or resistance between light blue and green. When the switch is flipped to lo-beam, the opposite is true.
I hope this is useful to someone. I’m not a Yamaha service tech person nor work in that end of the service sector, just a messenger, so don’t shoot me if I’m wrong. :thumbup:
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