I've been driving an S197 manual V6 for about 6 years now, and I've had this weird electrical problem for about the past 6 months.

Ordinarily, when the engine is warming up or driving at highway speeds, everything performs as normal. However, after the engine is warmed and when driving at speeds below 45 mph (including idling) I get very consistent voltage spikes which lug the engine and cut power to all of my electronics except the headlights, 12v socket, and cluster. This will happen for a solid 2-3 minutes and then return to normal for a random period of time. I'm leaning towards voltage regulator, but I feel like it would fail outright rather than intermittently.

Also this is my first post ever, so hello everyone!