I did it - I got the signal to change! The next time I came to this intersection, again, there weren't any cars to trigger the sensor. This time though, I moved to the center of the lane and rolled up to where my crankset was even with the stop line. There are no cuts in the pavement so, I don't know where the sensor is. But this did it! I'm exceptionally happy about it.
Thanks to all for your input on this thread.