Car Voltage Tester Tester for automobile electric and electronic circuits. Its low power consumption of 1.5mA is suitable for locating faults in electronic components where conventional lamp testers may cause damage. It has a crocodile clip on one end, and a tester with LED display and probe tip. The bright LED display indicates voltage and polarity. Particularly suitable for trouble shooting in wiring harnesses with catch hook to reach any wire and a pricking needle to probe through the insulation.