Thanks!

Is there a way to "check" the voltage regulator on these, or should we just replace it? Also dumb question, where is it located on a '88 300SEL? I drove the car the other evening... started out of a parking lot. I noticed the radio had went off, came back on then the car went black (car turned off, headlights went off, everything). It was black for a moment, then I was able to restart it and come home. We need this fixed now.

Thanks!