If one of your accessories doesnt come on and you suspect the relay is bad you can perform a few simple tests. If a component that is fed with electricity through a relay see how car electrical systems work terminal of the battery to the feed terminal on the component thereby bypassing the relay and supply wiring.
Wiring Diagram Car Horn Relay Car Horn Relay Car Sounds
What is a relay in a car. The main relay of an automobile is undoubtedly one of the most important and essential components of a car. Relays are located all over a car truck van suv or hybrid. A classic example is the system used to start a car when someone turns an ignition key the ignition does not interact directly with the car battery. Car relays are usually controlled by another switch such as your car horn button headlight switch circuit or power window door lock switches. The heart of a relay is an electromagnet a coil of wire that becomes a temporary magnet when electricity flows through it. A car relay is a electro magnetic switch that uses a small amount of current to control a larger amount of current.
A relay is an electromagnetic switch operated by a relatively small electric current that can turn on or off a much larger electric current. Instead it activates a relay which passes the signal on so that the car can start. It consists of a set of input terminals for a single or multiple control signals and a set of operating contact terminals. Fuse block covers often have an electrical schematic detailing the position and location of fuses and auto relays within the block. If the component still does not work it is faulty. Automotive style miniature relay dust cover is taken off a relay is an electrically operated switch.
An electrical relay is a switch that is under the control of another circuit. It controls the computers and the entire fuel system of your car. How they work is by a wire wound magnetic coil that when excited by a electric current moves a mechanical spring contact inside the relay completing a circuit. A typical car can contain up to twenty automotive relays and they can be located throughout the vehicle. If it works then the supply is faulty and the fault will be in the relay or the connections to it. However common locations for their installation are in the engine compartment behind the kick panels and underneath the dash.
Whenever you operate a switch to an accessory in your car that carries a lot of current such as the lights wipers or horn you run a small amount of current through a relay which in turn closes contacts to operate the accessory.