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Aircon Outdoor Fan Motor

The outdoor fan removes heat from the outdoor coil. If it slows down, heat builds up inside the system and cooling drops. This is often mistaken for a compressor or refrigerant problem.

What This Part Does

Your aircon removes heat from your room by moving it outside. The outdoor coil releases that heat into the air. The outdoor fan motor makes that happen.

It pulls air through the outdoor coil. This keeps the coil temperature from rising too high.

When the fan slows, the outdoor coil heats up. The system cannot reject heat fast enough. Cooling output drops — not because the refrigerant is low, but because the heat has nowhere to go.

How You Would Notice

Cooling starts normally, then weakens the longer the unit runs. The room gradually gets warmer instead of holding temperature.

The outdoor unit may feel much hotter than usual when you walk past it. In some cases the system trips a protection cutout and stops.

The pattern is heat-related and time-dependent. It is worse on hot afternoons.

  • Cooling starts fine then drops after extended running
  • Outdoor unit feels unusually hot to the touch
  • System trips or restarts after longer runs on hot days

It Might Not Be The Fan Motor

A weak run capacitor can also reduce outdoor fan speed — without the motor itself failing. Same symptom, cheaper fix.

A dirty outdoor coil restricts airflow through the unit. The fan runs at full speed but cannot move enough air through clogged fins.

We check the capacitor and the coil condition before we look at the motor.

How We Check

We check the run capacitor first. If it is weak, we replace it and retest before going further.

We then check the outdoor coil condition. A dirty coil can trap heat even with a working motor.

If both check out, we measure fan speed and current draw. Below-rated speed with a clean path and healthy capacitor points to motor failure.

We only recommend motor replacement when the data supports it.

What We Find And What Happens Next

Most outdoor heat issues are resolved by capacitor replacement or coil cleaning. Motor replacement is needed when speed data confirms under-performance.

What We Find And What Happens Next summary table
FindingNext Step
Capacitor weakReplace capacitor, retest cooling
Outdoor coil heavily cloggedChemical clean outdoor coil, retest
Motor speed below targetReplace outdoor fan motor

About The Repair

Outdoor fan motor replacement is a moderate repair. The motor sits in the outdoor unit and requires some disassembly to access.

If a technician recommends motor replacement without checking the capacitor and coil first, ask what was measured.

Speed data should support the recommendation.

After Replacement

A replaced outdoor fan motor should restore full heat rejection. Cooling should stay stable even on long runs in hot weather.

If cooling still degrades over time after motor replacement, the coil condition or refrigerant charge may still need attention.

We verify outdoor running temperature after every motor replacement.

When We Tell You To Wait

If cooling drops only on the hottest afternoons and recovers overnight, the system may be marginal but not failed.

A coil clean may restore enough heat rejection to resolve the issue without motor replacement.

We will tell you on-site which issue is driving the problem.

Common Questions