HVAC diagnostic - information provided to me from property management suspect a bad compressor. started diagnostic with testing and inspecting compressor. windings tested good, no direct shorts, ohmed windings good within specifications of manufacture, checked for any open circuits none. compressor should operate. Inspected all electrical wires good, tested dual run capacitor found capacitor is oversize for unit should be a 30 MFD has installed a 35 mfd. overtime will cause compressor to go bad. turned system on compressor started with no problems. checked refrigerant pressure found system low on refrigerant R22 causes a leak in the system undetermined where no big visible signs. inspected evap coil / air handler. Tenants complaining of low airflow upstairs found that to be caused by low airflow on return side no easy way for unit to cycle return air as well as blower motor and wheels are plugged / dirty restricting the air movement. Options to provide cooling back into property. R