The SAE (Society of Automotive Engineers) connector standard is
a family of all-weather low-voltage, medium current
connectors. It is defined by a standard contact form,
spacing, and arrangement, and in certain motor vehicle
applications, the purpose of each conductor is also
specified. For our purposes, suffice it to say that on the
side of the connection that produces the power (battery side), the
rubber-shrouded female conductor is the hot wire, going to the +
terminal. The most common place for an SAE connector in the
life of the average person, is the connection used to plug in a
trailer towed behind a vehicle, so the lights on the trailer work
in sync with the lights on the car. In motorcycling, the
two-conductor version has been adapted by many companies as the
standard power connector for 12V systems. Among the companies
supplying SAE power connections on their products are:
Aerostich, Battery Tender, CyclePump (sp?) and older Gerbing
equipment.