video of my charging gauge...whats it doing?

Sort of like this even though this is the Ammeter on my car:

[ame="https://www.youtube.com/watch?v=hUG7xYJIu0Y"]1974 Plymouth pulsating lights - YouTube[/ame]

I found that spending an afternoon going over all the grounds including battery to engine, battery to body, under the regulator and making sure the ground strap between the engine and body(not the negative cable) was in place essentially cured all these weird issues.