A relay can be checked with a jump cable, a voltimeter, an ohmimeter or a test light. If the terminals are accessible and the relay is not controlled by a computer, the fastest method will be a jump cable and a test light. If the voltage is not present, the relay coil is defective.

Does AutoZone change relays?

After conducting a simple electrical test, you can indicate if you need to replace an ignition relay. AutoZone has the solution for replacing relays at an affordable price so you can be back on the road in no time.

How do you check a relay if it's bad?

The only tool required to check a relay is a multimeter. With the relay removed from the fuse box, the multimeter set to measure DC voltage and the switch in the cab activated, first check to see if there are 12 volts at the 85 position in the fuse box where the relay plugs in (or wherever the relay is located).