Ruud air conditioner runs but makes loud buzzing or humming at the outdoor unit; fan may not start or is slow to start.

Safety first: Capacitors store electrical energy. Turn off power at the disconnect and verify with a meter. Discharge the capacitor before handling.

• Step 1 – Observe operation: If the fan blade is not spinning but starts when pushed with a stick (do this only briefly and carefully), the capacitor is likely weak.
• Step 2 – Access capacitor: Remove the Ruud condenser control panel cover. Locate the metal can capacitor labeled with µF and voltage ratings.
• Step 3 – Discharge and inspect: Discharge the capacitor by bridging terminals with a resistor or insulated screwdriver. Look for bulging top, rust, or oil leakage.
• Step 4 – Test capacitance: Remove wires (note positions) and test with a multimeter that has capacitance mode. Replace if more than ±10% out of spec.
• Step 5 – Install correct replacement: Use a capacitor with the exact µF ratings and equal or higher voltage rating, approved for HVAC use.