The lower LED harness is specifically for the Yamaha YZ250F(14-18), YZ250FX (15-17) and YZ450F(14-17), YZ450FX (16-17) . This harness Includes an On/Off handlebar switch (See part #129006 for switch details.) This harness is for non-electric start Yamaha YZ-F models and is only designed to run a headlight. For electric start models, the universal motorcycle harness (611049) will be needed to run lights.
Some 2017 models have electric start and will need harness 61-1049 to run lights. This harness is only designed to run a headlight.