Abnormal Waveforms
WARNING: This page is about a different car, the 2004 Mitsubishi Eclipse. However, it is still accessible from the selected car via links, so may be relevant.
The size of the waveform patterns can differ greatly, depending on the adjustment of the variable knob on the oscilloscope. See Fig 1 .
Identification of abnormal waveforms is easier when there is a large output current (regulator is not operating). Waveforms can be observed when the headlights are illuminated.
Check the conditions of the generator malfunction light (illuminated/not illuminated) also, and carry out a total check.