Start capacitor test (and its relay or PTC)
Start capacitors are higher-µF electrolytic parts that are only in the circuit for a moment at start, removed by a relay, PTC or centrifugal switch. They fail open, shorted or bulged, often because the switching device kept them in circuit too long.
Single source ~20 min moderateBrands: All
Before you start
- Power off and verify 0 V
- Discharge through a resistor and verify 0 V before touching terminals
- Match µF range and voltage rating exactly as printed or higher voltage
Diagnostic steps
Unlock all 3 steps with expected values
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