Turn off power to the air conditioner unit at its disconnect switch. Put on safety glasses. Connect the wire lead on the grounding rod to the air conditioner's green chassis ground lug screw. Loosen the lug and place the lead connector beneath the ground lug and tighten the terminal firmly.
Touch the probe to one terminal of the capacitor and hold it there for 20 seconds. Repeat this step for each terminal on the air conditioner's capacitor. Some air conditioner units place two capacitors inside one housing. These capacitors have three terminals.
Hold the screwdriver by the insulated handle. Touch the tip of the screwdriver to a capacitor terminal, then allow the screwdriver shaft to touch another terminal. A charged capacitor will cause a spark, but the capacitor will also discharge. Do this for all three terminals. This ensures the capacitor is fully discharged to earth ground.