How to know if a relay is bad in a car.
When you operate a switch to an accessory in your car that carries a lot of current, you run a small amount through a relay which closes contacts to operate the accessory.If you suspect the relay is bad and one of your accessories doesn't come on, you can perform a few simple tests.The location of your relay can be found in your owner's manual or under the hood.
When you operate a switch to an accessory in your car that carries a lot of current, you run a small amount through a relay which closes contacts to operate the accessory.If you suspect the relay is bad and one of your accessories doesn't come on, you can perform a few simple tests.The location of your relay can be found in your owner's manual or under the hood.
You can tell your friend to touch the relay while you operate the switch for the accessory that isn't working by turning the key to the "Accessories" position.When the relay operates, your friend should feel a click.You have a bad relay if not.
Put a short piece of wire into the two connections of the relay that make contact when the coil pulls them together.There is a diagram of the pins on the relay.They should be labeled "Common" and "Normally Open"The pins on the Bosch automotive relay are 30 and 87.