If your vehicle is showing a/c cuts out or stops blowing cold intermittently, here are the most likely causes and the parts you'll need to fix each one.
The most common cause of intermittent A/C is a slow refrigerant leak. When the charge is slightly low, the system pressure drops too much during operation, causing the low-pressure safety switch to turn off the compressor until the pressure equalizes again.
As the compressor clutch wears down over time, the physical gap between the clutch plates widens. When the engine bay gets hot, electrical resistance in the clutch coil increases, weakening the electromagnet so it can no longer pull the clutch in, causing the A/C to stop until it cools down.
Often caused by adding too much refrigerant using DIY 'A/C in a can' kits. The excess refrigerant causes system pressure to spike, which trips the high-pressure safety switch and shuts off the compressor to prevent catastrophic system damage.
The electrical relay that sends power to the A/C compressor can wear out internally. As the relay heats up during continuous use, the internal contacts may separate, cutting power to the compressor intermittently.
If the condenser cooling fan fails, the refrigerant cannot shed its heat, causing system pressures to skyrocket—especially when idling or in stop-and-go traffic. The high-pressure switch will shut the system down to protect it.
A severely clogged cabin filter, slightly low refrigerant, or a faulty temperature sensor can cause the evaporator coil inside the dash to freeze into a block of ice. This blocks airflow, causing the vents to stop blowing air until the ice melts.