Why does my multimeter not go to zero in the ac volts mode?
If it is a true-rms ac multimeter, such as the 17X or 8X, it will not zero and should not be zeroed. Most of these true-rms type multimeters have a minimum ac voltage and current level specification for both the ac volts and ac current modes, typically specified from 3% to 5% of range. When a signal is applied above the specified minimum level, the meter will meet its accuracy specifications. You will find this specification in the specification section in the rear of the user manual.