Normal normal normal.

Anytime an accessory kicks in that takes some power from the engine, your lights will slightly dim.

Our AC compressor kicks in whether the AC is on or off - 99% of the time, that's the flicker. FoxyMazda - during times when the power steering pump is working hard, it, too, takes power from the engine. Less juice to spin the alt = less juice FROM the alt.

This is totally normal, but generally should only happen at idle. On the highway, your car should be revving enough to compensate for any drop in alt. output.

~HH