I'm going to presume you are talking about the motor driving the car's air ventilation and heating / cooling system inside the passenger compartment. Typically, it's located underneath the heat exchanger. Usually found right against the engine f...
A carbuncle is a cluster of boils, draining pus onto the skin. It is usually caused by bacterial infection, most commonly with Staphylococcus aureus or Streptococcus pyogenes, which can turn lethal.
A carbuncle can simply be defined as a multiple furuncles grouped together. A carbuncle usually involves the deeper layers of the skin - the subcutaneous fat. It looks like a large, red nodule that is hot and may have visible layers of pus just beneath the surface of the skin. More about carbuncles.