Extruder Fan 1 Controlling an LED?

Is it possible to control an LED from Extruder Fan 1 if you only have a single hotend connected? I tried using the M106 command, but it only turns on Extruder Fan 0. Do I need to enable the 2nd Extruder in Marlin? If so, judging by how I could only find command M106 it looks like both fan outputs would turn on similarly and not be individually controlled.