How To Test A Car Ground Wire With A Multimeter. Connect a jumper wire between one wire end and the car frame. Similarly touch the other multimeter cable to the power.
The grounding wire in a vehicle connects with its metal frames to offset a sudden power surge. Red represents the positive terminal while black is the negative - terminal also ground. If you are grounding an accessory to the engine its good practice to run a ground wire directly to the alternator case and make sure there is no paint between the starter and the engine block mounting surface.
Now prepare the multimeter for examining the 3 wire sensor.
Examine the state of the multimeter before and after each use. If you are grounding an accessory to the engine its good practice to run a ground wire directly to the alternator case and make sure there is no paint between the starter and the engine block mounting surface. Connect the black lead of the multimeter to the ground terminal of the battery. Disconnect the wires at their corresponding components at both ends using a screwdriver.
