Quick visual check
Power off, disconnect, and open the motor housing or pump terminal box. The capacitor is a metal can with two terminals, usually black or aluminium, often labelled with the µF and voltage on the side.
- Bulging top or bottom: the can has rounded out. That’s electrolyte expansion. The cap is dead.
- Leaking oil or sticky residue: same diagnosis.
- Burnt smell or discoloured plastic: overheated. Dead.
- Cracks in the casing: physical damage from vibration.
Multimeter test (more reliable than visual)
If the cap looks fine but the symptoms point at it, a multimeter with a capacitance setting confirms the diagnosis in under a minute. Discharge the cap first: short the terminals through an insulated screwdriver for 10 seconds. Then:
- Disconnect both wires from the cap.
- Set the meter to capacitance (µF) mode.
- Probe across the two terminals.
- Read the value. A healthy cap is within ±5% of its label (motor run) or ±10% (motor start).
A cap reading 0 µF, OL (open), or significantly below the printed value is failed. Replace it.
What to order
Match three things: µF, voltage, and body code. The µF must match the label, within ±5%. The voltage rating must be equal or higher than the original. The body code (CBB60, CBB61, CBB65, CD60) determines the physical shape: match it so the new cap fits the bracket.
Not sure of the exact spec? Use the find-my-part wizard.