Did some more testing on Pepboys Fog LEDs. The Lithium battery supplies 3.4 volts and the regulator in the harness provides 5.7 volts. The regulator does not pulse to increase light output. Wayne looked at it and it is a non linear (linear = quiet) DC to DC buck regulator that is a switching regulator (switching = noisy). In this first scope pic DC = bright lines and hash is haze above and below = noise. Amplitude is ~ 600 to 800 milivolts.
Y9-02-22