Wire diagram for a 12v on/off switch controlled relay. This is just one example of controlling a relay to switch a 12v accessory (eg fog lamp, 12v fan, etc) on and off.
How to Wire a 30/40amp Relay
Wire diagram for a 12v on/off switch controlled relay. This is just one example of controlling a relay to switch a 12v accessory (eg fog lamp, 12v fan, etc) on and off.