It starts, runs a few minutes, and quits.

Short cycling means the system starts, runs for a short time, shuts off, and starts again soon after. It is a symptom rather than a fault, and the list of things that cause it runs from free to expensive.

What they have in common is that the compressor takes the punishment. Starting is the hardest thing it does.

Start with the thermostat

Where is it mounted? A thermostat in direct sun, above a lamp, on a wall with a duct behind it, or in a hallway with no airflow will read a temperature the rest of the house is not at. It satisfies early, shuts down, then the real room temperature reaches it and it starts again.

Is there a short cycle or swing setting? Some thermostats expose a cycle rate or differential. Set too tight, it will do exactly this.

Then the cheap mechanical causes

A filthy condenser coil. The classic Phoenix version. Head pressure climbs until the unit trips its own high pressure safety, then it cools down enough to restart. On a mild morning it runs fine. At three in the afternoon it cycles.

A restricted filter or blocked return. Starved airflow across the evaporator coil can trip a low pressure safety, or start frosting the coil, which ends the same way.

A failing capacitor. A motor that struggles to start may get going, run briefly, and drop out on thermal overload.

Then the ones that cost

Low refrigerant. Low charge trips low pressure safeties. It also means a leak, and the leak is the job.

A TXV hunting. A metering device that cannot settle will swing the system between starved and flooded, and that reads as erratic cycling.

A failing compressor dropping out on its internal overload. This one usually comes with high amp draw, which is measurable.

And the one that is not a fault

An oversized system. A unit with more capacity than the house needs cools the air to setpoint fast and shuts off, over and over. It never runs long enough to dehumidify, so the house feels cold and damp rather than comfortable, and the compressor racks up starts.

Nothing is broken. It was specified wrong, probably years ago, and no part replacement fixes it. Knowing that is still worth the visit, because it stops you buying parts that will not change anything.

Correct sizing comes from a load calculation on the house, not from tonnage rules of thumb about square footage.

What a visit measures

Run times and cycle counts, pressures on both sides, amp draws, delta T, and the state of both coils. The pattern across those numbers is what separates a dirty coil from a dying compressor, and you keep the record either way.