Understanding The 90-340 Relay Wiring Diagram

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90 340 Relay Wiring Diagram Wiring Diagram

Relay wiring diagrams are an essential tool for any technician or engineer working on electronic systems. Knowing how to read a relay wiring diagram can help you troubleshoot any issue with your system’s electrical components. The 90-340 relay wiring diagram is especially useful for understanding how to wire up a relay.

What Is a Relay?

A relay is an electronic switch that is used to control the flow of electricity in a circuit. The way a relay works is by controlling the amount of current that is allowed to pass through the circuit. This is done by using an electromagnet to open and close the relay contacts which control the current flow. Relays are commonly used in industrial and automotive applications.

Reading the 90-340 Relay Wiring Diagram

The 90-340 relay wiring diagram is a visual representation of how the relay works and what components are required to complete the circuit. It consists of two diagrams, one showing the internal components of the relay and the other showing the external components. On the internal diagram, each component is labeled with its respective terminal number. The external diagram shows the connection of the relay to other components in the circuit.

Steps for Wiring a 90-340 Relay

To wire a 90-340 relay, follow these steps:

  • Connect the power source to terminal 1 of the relay.
  • Connect the load to terminal 2 of the relay.
  • Connect the control signal to terminal 3 of the relay.
  • Connect the ground to terminal 4 of the relay.

Once all the connections are made, the relay should be ready to operate. To test the relay, apply power to the power source and then apply the control signal to terminal 3. If the relay is operating correctly, the load will be powered on.


The 90-340 relay wiring diagram is a helpful tool for understanding how to wire a relay. By following the steps outlined above, you can easily wire a relay for any application. With a little practice and patience, anyone can become proficient in reading and understanding relay wiring diagrams.