An operator of a eighteen wheel truck needs to know more about its operation than just driving it. In addition to making sure it is road worthy and safe, everything needs to be connected to each other properly and securely. In order to have properly functioning lights for the trailer, the pigtail line must be attached to the trailer from the truck.
The pigtail connector, so named because it resembles a pigs tail, is only one component of all the connections that need to be made. However, it is the connection that supplies all the electrical needs to the trailer. The coil in the cable allows the truck to turn without the cable being disconnected.
The pigtail is attached from the back of the tractor to a trailer with a green cable. The part that is to be attached is called the female plug and it is connected to the male outlet. It is mounted on the back of the tractor and is a static connection.
It is important for the operator of the vehicle to be aware of every working part of their machine. They are always checking their mirrors which are mounted on the doors to make sure that the lighting is functioning on the back of a tractor. The pigtail line is generally two to three feet long, and this makes for easy turning around corners without the electrical connection being disconnected.
In order to get the electric power into the trailer, the pigtail is connected to the tractor, which is connected to the alternator inside the engine. It is the alternator that is responsible for all of the the electrical power to the entire vehicle. The connector on the truck is hardwired to the truck, usually on the back of the cab.
With a trailer supplied with power, this ensures that the running lights and brake lights will be operational while the truck is moving. It will also supply lighting to the inside of the trailer. It is very dangerous to operate a tractor and trailer without it being properly lit.
A tractor trailer operator is very well educated in the operation of their vehicle. Making sure that the pigtail connection is properly secure is only one of the many checks that are to be done prior to operation. In order to have a properly functioning trailer, all connections from the tractor must be secure.