wires

Hi All. New owner here. I was wondering what these 4 disconnected plugs in my engine bay might be. I have a pre facelift '99 2.8 manual.

Radio installation has provided harder than I anticipated. I used a multi meter to determine constant, earth and ignition wires. I used a 9V battery to check for the correct speaker wires. Instead of one the speakers popping I heard a popping sound from behind the instrument cluster! Now I have...