Relay
A relay is an electrically operated switch that lets a small current control a larger one.
What is Relay?
Relays switch fans, fuel pumps, horns, lights and more. They often sit in the fuse box. A typical automotive relay has four or five pins: two for the coil and two or three for the switched contacts. Solid-state relays have no moving parts.
How it works
Current through a coil creates a magnetic field that closes the switch contacts.
Why it matters for your car
A failed relay can stop a component from working; swapping with an identical relay is a common test. A clicking relay that does not power its load can have burnt contacts even though the coil works.
Other terms
- Automated Manual Transmission (AMT)
- Engine Bearing (Plain Bearing)
- Engine Code
- Front Splitter
- Lowering Springs
- Number Plate Light (Licence Plate Lamp)
- Oil Filter
- Open Differential
- Pre-purchase Inspection
- Rain Repellent (Glass Coating)
- Ratchet Strap
- Ride Height
- Snow Foam
- Supercharger
- Third-Party Liability Insurance
- Tonneau Cover
- Torque Converter
- Tyre Changer (Tyre Fitting Machine)
- Tyre Repair Kit (Sealant Kit)
- Wheel Balancing