A Simple Relay Tester That Will Easily And Quickly Test Most 12 And 24 Volt DC Automotive Relays. Tests relays by simply clipping the test leads onto the relay terminal pins using a 12 or 24v DC power source. Tests a wide range of 4 and 5 pin relays. Including shielded, nonshielded, relays with different pin sizes and 4 pin normally closed relays that other testers may incorrectly show fail. Automatically determines the relay configuration so the fully insulated gator clips can be connected in any order. Eliminates guesswork because you don�t need to connect to specific pins, like other testers. 45" power leads with heavyduty gator clips provide a secure connection to the power source.