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 4.5mtr cable allowing access to the rear of the vehicle and supplied with instructions.