If you want to avoid splicing, you can tap into the brake light circuit up under the fairing on the front left of the bike where the accessory harness plugs in. Please verify the following wire colors - you could get some Hitachi OEM style plugs and keep it CLEAN! I spliced into the wires down by the taillights - wasn't real clean or neat.
Anybody else that could verify this please chip in.
From an old post somewhere?
"There is also an auxiliary accessory plug on your ST. This option connector is on the left side of the bike under the gas tank, and has 6 wires.
Green is ground. Light blue is hot when the right turn signal is on.Orange is hot when the left turn signal is on.
White/Green is hot when the brake light is on. One Red/Green wire is an available spare circuit fused at 15 amps, listed in your primary fuse box (switched power) as ACC or Hazard/ACC, on when the ignition key is on ON or ACC. The sixth wire is also Red/Green, on always, fused at 10 amps, listed in your secondary fuse box (direct to battery power) as Battery / Clock Backup. This wire is always hot. So, you can tell them apart by turning your bike off and seeing which one is still hot. "