Flickering or pulstating Headlights

I've mentioned ripple a couple of times.
Basically its the left over alternating current waves when the electicity was converted to DC.
If we had an oscilliscope we could see the voltage over time.
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Its usually very small compared to the voltage, so we don't see it on the meters. Something like 0.1 Volt

If a diode is bad, then that portion is not rectified and then it looks like we're seeing a bad ripple.
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