Wiring Diagram for 5 Pin Relay

Hello there, welcome to our article on the wiring diagram for a 5 pin relay. In this comprehensive guide, we will walk you through the step-by-step process of understanding and implementing a wiring diagram for a 5 pin relay. So, let’s dive in and explore this topic in detail.

1. What is a 5 Pin Relay?

A 5 pin relay is an electromechanical device that allows a low-power circuit to control a high-power circuit. It consists of five pins, namely the coil input pin, the common pin, and three normally open (NO) or normally closed (NC) pins. These pins enable the relay to switch between circuits, making it an essential component in various electrical systems.

2. Understanding the Wiring Diagram

The wiring diagram for a 5 pin relay provides a visual representation of the connections between different components. It shows how the relay is wired to other electrical devices and illustrates the flow of current. By understanding the wiring diagram, you can easily install and troubleshoot the relay system.

3. Wiring Connections

When wiring a 5 pin relay, it is crucial to connect the right wires to the designated pins. The coil input pin is connected to the power source, while the common pin is linked to the circuit requiring control. The NO or NC pins are connected to the load or device that needs to be controlled, depending on the desired functionality.

4. Advantages of Using a 5 Pin Relay

There are several advantages of using a 5 pin relay in electrical systems:

  • Versatility: A 5 pin relay can be used in a wide range of applications, including automotive, industrial, and residential.
  • Reliability: Relays are known for their durability and ability to handle high currents, making them reliable for controlling heavy-duty electrical devices.
  • Easy Installation: Wiring a 5 pin relay is relatively simple, and with the help of a wiring diagram, even beginners can install it correctly.
  • Protection: Relays provide an additional layer of protection by isolating the control circuit from the high-power circuit, preventing damage to sensitive components.

5. Disadvantages of Using a 5 Pin Relay

While 5 pin relays offer numerous advantages, there are a few disadvantages to consider:

  • Complexity: Some wiring setups may require multiple relays, increasing the complexity of the system.
  • Cost: Compared to other control devices, relays can be relatively more expensive.

6. Alternative Wiring Diagrams

Aside from the standard wiring diagram for a 5 pin relay, there are alternative wiring configurations available. These alternatives can provide different functionalities or cater to specific requirements. Some common alternatives include:

  • Double Pole, Double Throw (DPDT) Relay: This relay configuration allows for the control of two separate circuits simultaneously.
  • Time-Delay Relay: Also known as a timer relay, it provides a delay in switching the circuits, allowing for time-based control.
  • Latching Relay: Latching relays have two stable states and require a pulse of current to switch between them. They are commonly used in memory circuits.

7. Wiring Diagram for a 5 Pin Relay – Step by Step

In this section, we will provide a detailed step-by-step guide on how to wire a 5 pin relay:

Pin Function Wire Color
Pin 85 Coil Input Red
Pin 86 Coil Input Black
Pin 30 Common Yellow
Pin 87 Normally Open (NO) Green
Pin 87a Normally Closed (NC) Blue

1. Connect the red wire to pin 85 of the relay and the black wire to pin 86. These wires supply power to the relay coil.

2. Connect the yellow wire to pin 30 of the relay. This wire is the common connection for the control circuit.

3. Connect the green wire to pin 87 of the relay. This wire controls the normally open (NO) circuit.

4. Connect the blue wire to pin 87a of the relay. This wire controls the normally closed (NC) circuit.

8. Frequently Asked Questions (FAQ)

Q: Can I use a 5 pin relay in a 4 pin relay application?

A: Yes, you can use a 5 pin relay in a 4 pin relay application. Simply ignore the extra pin and connect the necessary wires to the corresponding pins.

Q: How do I test a 5 pin relay?

A: To test a 5 pin relay, you can use a multimeter to check the continuity of the pins and the functioning of the coil.


In conclusion, a wiring diagram for a 5 pin relay is essential for understanding and implementing the proper connections in electrical systems. By following the provided wiring diagram and step-by-step guide, you can easily install a 5 pin relay and utilize its advantages in controlling various circuits. Remember to always refer to the specific wiring diagram for your application to ensure accurate connections. If you have any further questions, please refer to our FAQ section or consult a professional electrician.