Air conditioner not cooling
Ranked from 2,400 repairs on split-system condensers with this symptom. Narrow it below and the ranking recomputes.
Before you start — Kill the power, then discharge the capacitor electrical · refrigerant safety
Pull the disconnect at the outdoor unit AND switch off the breaker. A run capacitor holds a dangerous charge for a long time after the power is off — discharge it across an insulated resistor before you touch the terminals, and never bridge them with a screwdriver. Anything that opens the sealed refrigerant system is EPA-608 licensed work.
Narrow it down
My outdoor AC unit doesn't run at all — what's wrong?
A condenser with no signs of life is usually not getting power to the compressor and fan: the contactor accounts for about 48% of these repairs. Check the disconnect and the breaker first — both are free — then look at the contactor's contact faces. A failed capacitor (22%) can also leave the unit silent rather than humming.
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Also check — 48%48% of matching repairs
Welded or burnt-out contacts, or a dead 24V coil, leave the outdoor unit with no power at all while the indoor blower runs happily.
Try this first: Free first: confirm the disconnect is in and the breaker hasn't tripped. That is a surprising share of "dead" units.
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Also check — 22%
TRD-45550
45+5 µF 440V Dual Run Capacitor
320 in stock · ships today
$18.40 Pro price $15.64 save $2.76 (15%)22% of matching repairsA capacitor that has failed open — rather than drifted — can leave the unit silent instead of humming.
The remaining 30% of matching repairs resolved without a replacement part — a filter, a reset or a thermostat setting.
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