How To Test Relays

In this video, I show you how to test relays. There are two parts inside a relay, a trigger and a switch. That is all you need to remember. I show you how to find the trigger and the switch. The trigger has a resistance of about more or less 100 ohms. Once you find the trigger terminals, the remaining terminals are for the switch. The switch has two types also, "normally open" and "normally closed". Usually the trigger has thin wires and the switch has thick wires. This is because you can apply a small amount of current to the trigger and the switch can handle large amount of current. Example, the headlights of a car need a high current to operate, while the the tail lights with long thick wires that travel from the car battery to the back of the car also need a high current.