Pics worked that time. Those wires are for the "Water in Fuel" light on the dash. The lines don't go inside the fender at all. I would follow the "in" line from the separator downward and back toward the selector valve; I'll bet when you reach the point where it runs along the frame, right about where your puddle is, you'll find a leak in the line. Or the leak may be further back, and the fuel just clinging to the outside of the line and eventually dripping off there.
That said, I've heard that those Stanadyne separators are notorious for leaking. Sorry to tell you this, but I've read that if you "pull its finger" (that is, pull the ring), when you let it go, whatever it opens sometimes doesn't fully close again and you've got a leak on your hands. I've been lucky, have resisted the temptation to touch mine, and it's been dry. But I've been looking at the generic filter mounts on eBay, Amazon, etc., and compatible spin-on separator/filters. Just haven't pulled the trigger yet. I figure when I get one and decommission the Stanadyne, I'll just do without the light, and keep an eye on the separator. Probably the best thing you can do to keep water out of your fuel is to buy diesel at places you know are reputable.
Dunno what it is about pics on this forum; they seem to work about half the time. And when they don't, they don't seem to warn the poster. They just create a bunch of bogus links with "Attachmentxxxxx"
