it is black and on the drivers side front of the motor
it is aluminum looking under the cap
I believe this is a warning for the brake pads.
The evaporator charging valve
the boiling point of refrigerant in a refrigeration or air conditioning system determines the pressure of the low side of the system
the purge unit exhaust port
Because mercury has an extremely low melting point. It is the only liquid metal at room temperature.
The only elemental metal that is liquid at standard pressure and 25 C is mercury, with symbol Hg.
Simply put, atmospheric pressure is the force exerted on a measuring point by the weight of the air molecules on top of that point. Standard atmospheric pressure, measured at sea level at 59F or 15C, is used as a reference point and is equal to 29.92 inches of mercury or 1013 millibars of pressure.
It is possible that the headlight door wiring is degraded to the point of not working. After nearly 50 years, it could be time to replace the wiring harness.
No. Mercury is a metal that is liquid at room temperature. Melting point is  -38.83° C (ie a solid below this temperature) Boiling Point is 356.73 °C (ie a gas above this temperature) (All at 1 atmosphere pressure)
Mercury has a melting point of -39.9
Go to this site and contact these folks. If they cant help, they might be able to point you in the right direction. http://www.dashusa.com/ford_trucks.htm Run1
sampling conditioning system is a group of equipment starting from the probe "take off point" , pressure regulator ,cooler or heater ,filters end with flow meter " to bring sample conditions to match required conditions for the analyzer