All the features of the Auto Probe but with an integral work light to aid use in dark engine bays plus an audible circuit tester for when the LED on the probe cannot be seen. A brilliant tool for the auto electrician and mechanic. Carry out the following tests on systems from 6V up to 24V quickly and efficiently: Polarity test. Power up components prior to fitting including: Cooling fan motors Fuel pumps Window/Sunroof motors Relays and Lamps Wiper motors Tests continuity in: Switches Diodes and Fuses Relays Wiring harnesses Detect short circuits. Locate bad earths quickly. Fitted with a sensitive short circuit protection device. Safe to use around vehicles electronic management systems. Power switch self test means no need to: Double check your circuit, tester on the vehicle’s battery. Reconnect hook-up clips to test polarity. Search for earth points. Burn out fuses locating faults. Run voltage drop tests. Fitted with 4.5 metre cable allowing access to the rear of the vehicle and supplied with instruction guide.