Which tool is commonly used for diagnosing electrical issues in trucks?

The multimeter is commonly used for diagnosing electrical issues in trucks because it is capable of measuring various electrical properties such as voltage, current, and resistance. These measurements are essential for troubleshooting electrical systems and components, such as batteries, alternators, and wiring. A multimeter allows mechanics to determine if electrical circuits are functioning properly or identify faults that may cause issues in the truck's performance.

The other tools listed serve different functions that do not primarily relate to diagnosing electrical problems. An odometer measures distance traveled by the vehicle, a torque wrench is used to apply a specific amount of torque when fastening nuts and bolts, and a compression gauge measures the compression pressure of an engine's cylinders. While these tools are important in vehicle maintenance and repair, they do not provide the electrical diagnostic capabilities that a multimeter offers.