Step 2 · Disconnect Battery Terminals
To safely begin testing, you need to disconnect the car battery. First, locate the battery under the hood. Using an appropriate-sized wrench (commonly 10mm or 13mm), loosen the nut on the negative terminal clamp (usually marked with a '-' symbol or black cover) and remove the cable. Then, do the same for the positive terminal clamp (usually marked with a '+' symbol or red cover). It's crucial to disconnect the negative terminal first to prevent accidental short circuits.