Warm air during a Pasadena heat wave is miserable. The usual suspects, and why a can of refrigerant often makes it worse.
Pasadena summers regularly push into the 90s and 100s, and there's nothing worse than turning on the A/C and getting a blast of warm air. The good news is that most A/C problems come down to a handful of common causes.
Your A/C is a sealed loop. The compressor pressurizes refrigerant, the condenser in front of the radiator sheds heat, an expansion device drops the pressure, and the evaporator behind the dash gets cold. The blower pushes cabin air across the evaporator and out the vents. If any part of that loop isn't doing its job, the air comes out warm.
This is the most common cause. Because the system is sealed, low refrigerant always means a leak: a hose, an O-ring, a seal, the condenser or the evaporator. Leaks are often slow, so the A/C gets a little weaker every summer until it's just warm.
The compressor is the heart of the system. If its clutch doesn't engage, or the compressor fails, there's no cooling at all. You may hear a noise when the A/C is on, or notice the clutch at the front of the compressor isn't spinning.
The condenser sits at the very front of the car, where road debris hits it. A rock can puncture it, and bugs and dirt can clog it. A blocked condenser can't shed heat, so the A/C may work on the freeway but blow warm in stop-and-go traffic on Colorado Boulevard.
At low speeds, the radiator fan pulls air through the condenser. If the fan fails, the A/C goes warm at stoplights, and the engine may start running hot too. That's a problem worth fixing quickly in summer. See engine repair for overheating.
Pressure switches, relays, fuses and wiring all control the compressor. A failed relay can make a perfectly good system stop cooling. Our electrical repair work covers these.
If the air is cold on one side and hot on the other, or the temperature changes on its own, a blend door actuator inside the dash may be the issue. A clicking noise behind the dash is a common clue.
If the air is cold but barely coming out, check the cabin air filter first. After smoky or dusty seasons, these clog fast.
A proper repair starts with a performance test and pressure readings, then leak detection. Once the leak or failed part is repaired, the system is evacuated and recharged with the exact amount your vehicle specifies. That's our approach to every A/C repair and recharge.
Spring is the best time to check your A/C. Call (626) 449-6252 or stop by 1323 E Walnut St #2 in Pasadena.
Smog checks, failed smog repair, check engine diagnostics and complete auto repair on E Walnut St. Honest answers and fair prices.