"The A/C is already running..." is probably misinformation. Specifically, YES it's cooling, but NO it's probably cycling the compressor. Hopefully it's normal compressor startup after every Off Cycle. If it's Short Cycle (thermostat problem, user turns off in error and immediately turns back on) then it's still got High Side Pressure and will take a lot of amps to start. That HF meter will measure Running Amps and God Forbid "Locked Rotor Amps" (meaning compressor didn't turn over due to some malfunction) but it won't capture "start amps" sometimes called "inrush current." All of this discussion relates to how a "smart" Start Kit (with electronics or relay but not simply PTCR) will help.
