One of my front fogs went out, so I went to buy a new bulb, but that didn't fix it. So I used the other working one to troubleshoot by stretching a wire across to see which wire (power or ground) was at fault. Although a multimeter showed ~12 volts potential difference, it turns out the power wire wasn't working. Traced it back to a connection point and removed and reconnected. It's the kind of connection that 1 wire fits into a hole in the other one.
Like this:
'''''__
-----__ <==------

I thought that was interesting.

Next thought, we were having a bad rainstorm and I wanted to use my rear fogs. They weren't working. Even the little LED in the switch wasn't lighting up. I thought maybe the contacts were bad, since both bulbs normally don't go out at the same time. I removed one of them, replaced it, and tried the rear fogs again- they worked. Are the rear fogs wired in series or something??

Nathan