The electrical contact a Plymouth Relay makes in completing a circuit is the means of how devices are activated on your vehicle. This is the clicking sounds that the relay makes when the circuit is activated that powers the electrical devices on your Plymouth.
The use of the Plymouth relay in providing the power to a device has several different reasons. One of the more common uses for the relay is so multiple devices can be activated simultaneously when the electrical circuit is supplied with power. This can be the activation of the blower motor along with a separate electrical motor to open the correct vent so the temperature control device performs the correct function.
The relay on the circuitry of an electrical device is directly connected to the power source that will supply the electrical current. Once activated the power is in most instances transferred to the device through the fuse before it reaches its destination. This is a safety precaution on your Plymouth just in case the voltage passing through this electrical device is too great which could damage the device.
The location of the relays for each device on your Plymouth is determined by the availability of space. On the schematic drawing, they appear next to each other, but in reality this is a very rare occurrence. Because the electrical impulse sent through them does not degrade over the limited space they will have to travel in the wiring harness of your vehicle, their placement just has to be where a place can be found. This is why under the dashboard of the vehicle generally looks like a jungle of wires and devices. These electrical devices can be placed there out of the way but still capable of performing their function on a constant basis.