Relays have become an important part of modern electric and electronic systems. They are widely used in automobiles, machines, and other equipment to control power circuits. One of the most common uses of relays is to control fans, especially in cooling systems. In this article, we will discuss a 5 pin relay wiring diagram for a fan in detail.
What is a Relay?
A relay is an electrical switch that is operated by an electromagnet. It consists of a coil, an armature, and one or more sets of contacts. When the coil is energized, it creates a magnetic field that pulls the armature to close the contacts. When the coil is de-energized, the contacts open again.
Relays are used to control power circuits because they can switch high currents with low currents. They can also isolate one circuit from another, which is important for safety and protection.
The 5 Pin Relay Wiring Diagram for Fan
There are many types of relays available for different applications. The 5 pin relay is one of the most common types of relays used in automobiles and machines. It has five terminals, which are numbered 85, 86, 87, 87a, and 30.
The 5 pin relay wiring diagram for a fan is as follows:
| Terminal | Description | Wire Color |
|---|---|---|
| 85 | Ground | Black |
| 86 | Trigger | Green |
| 87 | Output | Red |
| 87a | Not in use | Not connected |
| 30 | Battery positive | Yellow |
Terminal 85 – Ground
The ground terminal is connected to the chassis or ground point of the vehicle. This is the reference for the entire circuit and ensures that the relay operates reliably.
Terminal 86 – Trigger
The trigger terminal is connected to the source that will activate the relay. In this case, it is the wire from the temperature sensor that senses the temperature of the engine or other equipment. When the temperature reaches a certain level, the sensor sends a signal to the relay to turn on the fan.
Terminal 87 – Output
The output terminal is connected to the fan motor. When the relay is activated, it closes the contacts and allows current to flow to the fan, which turns on and starts to cool the engine or other equipment.
Terminal 87a – Not in use
The 87a terminal is not used in this wiring diagram. It is used in other types of circuits where a normally closed contact is required.
Terminal 30 – Battery Positive
The 30 terminal is connected to the positive terminal of the battery. This provides power to the relay and the fan motor when the relay is activated.
Frequently Asked Questions (FAQ)
What is the purpose of a fan relay?
A fan relay is used to control the operation of an electric fan in a cooling system. It turns on the fan when the engine or other equipment reaches a certain temperature and turns it off when the temperature drops below a certain level.
What is a 5 pin relay?
A 5 pin relay is a type of electromechanical switch that has five terminals. It is commonly used in automotive and machine applications to control power circuits.
How do I test a fan relay?
To test a fan relay, you need a multimeter and a wiring diagram. First, disconnect the relay from the circuit and check for continuity between the terminals using the multimeter. Then, apply power to the relay and check that the contacts close and the fan motor turns on.
What is the difference between a 4 pin and 5 pin relay?
A 4 pin relay has four terminals, which are numbered 85, 86, 87, and 30. It is used in applications where only one set of contacts is required. A 5 pin relay has an additional terminal, 87a, which is used for normally closed contacts. It is used in applications where both normally open and normally closed contacts are required.
Can I use a 5 pin relay for a 12V fan?
Yes, you can use a 5 pin relay for a 12V fan. The wiring diagram and terminal connections are the same as for other applications.
