Automotive Multi-Function Circuit Tester with LCDDesigned to test the electrical system of an automotive vehicle running on 12V or 24V. One of the great features is being able to activate components with positive or negative without using a jumper wire. This would, for example, allow you to send voltage to a relay that controls whether or not a fan switches on. You can quickly test the voltage and polarity of a circuit or whether it's short or open, check continuity, locate cylinders which are