VW Electrical troubles

I have a 1998 VW cabrio. It seems that now often when I hit a puddle the electric in my car completely goes off just for a couple of seconds- clock goes blank, the millage meter goes blank, the speed and RPM “thing” drop but the car is still running but bucks. Sometimes it bucks first sometimes it bucks during. Only once did the car just stop working altogether and when I finally got it started it smelled of sulfur (when left overnight the next morning it was like nothing happen). To boot now the wipers decide when they want to go on on their own. If anyone has any advice for me please share…Thank You!

There are lots of possibilities, but I would start with cleaning both ends of any cable connected to the battery. I would also suggest considering check out or replacing the main relay (I believe it is #109)