I recently had the opportunity to install a Diamond-Star headlight modulator on a GTS 250. The wiring is fairly straightforward, but the tricky part is finding a location for the optic sensor! The optic sensor is required in the States because headlight modulation is illegal after dark, and the sensor allows the modulation to function only in the daylight hours.
I wasn't about to drill a hole in this guy's body panels. I've seen another modulator install that had the sensor in the rubber boot that fastens at the foot of the mirror. I could have done this, but I figured that I'd try to take a slightly more challenging gamble at it.
(The first two photos are large, so I added them as links instead of posting the photos themselves.)
Mounting the optic sensor there is NOT as easy as you'd think! There's a circuit board and some other goodies that prevent one from just drilling straight through the back of the instrument cluster to feed the sensor through. I didn't have the camera yesterday when I started the project, so unfortunately there's no pics of the beginning... shame though, there's a LOT of fancy dremel work underneath that sensor.
Every wire touched in this project is soldered.