* Blend Door Actuator: This small motor controls the mix of hot and cold air. If it's malfunctioning or broken, it might be stuck in the hot air position, even though the compressor is working. This is a very common cause of this issue.
* Blend Door Cable (if equipped): Some Cavaliers might use a cable instead of an actuator. This cable could be broken, disconnected, or jammed.
* Stuck Blend Door: The blend door itself might be physically stuck in the hot air position due to wear, debris, or damage.
* Evaporator: While less likely if the compressor is running, a completely clogged or restricted evaporator core (the component that cools the air inside the cabin) could prevent cold air from reaching the vents, even with sufficient refrigerant.
* Low pressure switch: Although you say the freon is fine, a faulty low-pressure switch could be preventing the system from operating correctly, even if there's enough refrigerant. It's a safety device, and a malfunction can cause the system to shut down.
* Electrical Issues: A problem in the wiring to the actuator, compressor clutch, or other AC components could prevent the system from working properly. This could manifest as the compressor engaging but not actually cooling.
* Refrigerant Leak (despite initial assessment): A slow leak could be occurring, and your initial assessment might not be entirely accurate. A leak detection test by a mechanic is needed for verification.
Troubleshooting Steps:
1. Listen Carefully: When the AC is on, listen near the vents. Do you hear any unusual noises (like clicking or grinding) that might indicate a problem with the blend door actuator?
2. Check the Blend Door Actuator: This usually requires accessing it (often under the dashboard), sometimes by removing the glove box. Inspect it visually for obvious damage and try moving it by hand (carefully!). If it's stiff or doesn't move freely, it's likely the culprit.
3. Manual Blend Control (if applicable): Some Cavaliers may have a manual control for blending hot and cold air. Try manually switching the blend to full cold. If this doesn't work, the issue likely isn't the blend door control itself.
Recommendation:
Since several of these possibilities require some mechanical expertise and diagnostic tools, it's best to take your Cavalier to a qualified mechanic or auto AC specialist. They have the tools and knowledge to diagnose the exact problem and perform the necessary repairs. Trying to troubleshoot this complex system yourself without experience can lead to further damage.
