Where is the pigtail receptacle located?

The pigtail receptacle is an important component in the connection between the tractor and the trailer, essential for the electrical operation of the trailer lights and brakes. The correct answer indicates that the pigtail receptacle is located on the back of the tractor and at the front of the trailer.

This placement allows for a seamless and efficient connection, where the electrical wiring from the tractor can easily plug into the trailer’s electrical system to provide power for various functions such as brake lights, turn signals, and marker lights. Proper operation of these lights is critical for safety and visibility, especially when traveling on public roads.

The incorrect locations listed in the other options demonstrate misunderstandings of the pigtail receptacle's function. It is not solely at the front of the tractor, as it needs to interact with the trailer's system at the back. Being underneath the trailer is not standard because the pigtail requires accessibility for connection and disconnection. Lastly, having it inside the cabin of the tractor would not provide the necessary connection to the trailer, as it needs to be positioned to interface with the trailer’s electrical system directly.