Workshop reference
What are you testing?
Start from the system that is playing up. Every guide gives the meter setting, exactly where the red and black go, the reading you should see and what a bad one means.
Browse by system
All procedures
58 tests indexed, 18 with a full step-by-step procedure and interactive bench.
Open the full libraryWhat should it read?
Every typical figure in one place — ohms, sensor volts, current draw, charging, CAN and what OL actually means, each with the fault it points to.
Reference tablesIs that reading good or bad?
What OL really means, 1 ohm against 1 megohm, millivolt drop limits, drain in milliamps, plus fuse and cable sizing tables.
Reading the meterNeed a refresher?
Volts, amps, resistance and voltage drop explained with interactive vehicle maths — read it before or after the test.
Electrical fundamentals