I would begin with a wiring diagram that shows the location of where the ground is connected to the body. Don't be satisfied with looking at it; removed the screw, clean and reattach the connector.
Initially, you did not mention that the fog lights were not working. Is there any other information that may help?
Did you get the manuals? Did those include wiring diagrams?
Check relays (pull and clean the spades) and then positive wires, particularly where they are routed through areas that move (door jam, steering column), and connectors.
As for server errors, well the site seemed to function flawlessly before the ISP switch, so ...