Multimeters allow you to test the current, voltage and resistance of your automobile's electrical system. When you perform a test on your car's battery, you also need to test the other components of the charging system to determine whether the battery is failing.
Testing the resistance of the starter with a multimeter is a fundamental step in diagnosing vehicle charging system problems. A starter that shows high resistance will drain power from the battery faster than the alternator can recharge it.
Align one car ramp with each front tire of your vehicle. Drive the vehicle onto the car ramps. Place the vehicle in park and set the emergency brake. Turn off the vehicle.
Set one wheel chock behind each rear tire of the vehicle.
Lie down on the floor creeper and slide yourself under the vehicle. Locate the starter, which should be on the side or front of the engine.
Wipe the cable running to the starter with a rag. Inspect the cleaned cable for nicks in its protective sheathing, or a loose connection between the starter cable and the starter bolt. Tighten any loose connections with an adjustable wrench.
Connect the positive and negative leads of the inductive current clamp to the positive and negative ports on the body of the multimeter.
Hook the inductive current clamp over the power cable that runs to the starter. Turn on the multimeter, and set it to "Resistance."
Read the multimeter display as an assistant starts the engine. Compare the display reading with the starter manufacturer's specifications. If the resistance reading is too high, try replacing the cable. If the problem persists, the starter is likely to have internal problems, and may need replacement.
Shut the vehicle hood. Remove the chocks from behind the vehicle's rear wheels and drive it down from the ramps.
Wear safety glasses to avoid eye injuries when working under a vehicle.