My car's AC is blowing air, but it's not cold at all. It's been getting warmer outside, and this is becoming a real problem. The fan seems to be working fine.

Use a diagnostic scan tool to read ABS fault codes and test the functionality of each wheel speed sensor. Replace any sensor that is not providing accurate readings.

Visually inspect the ABS wheel speed sensors and their wiring for any obvious damage or debris. Clean any accumulated dirt or corrosion.

If the horn is determined to be faulty, it will need to be replaced. This usually involves accessing the horn located on the front of the vehicle.

With proper safety precautions and knowledge of your car's electrical system, you can attempt to apply power directly to the horn to see if it sounds. This helps isolate the issue to the horn itself.

A faulty clock spring can also cause horn failure, and often other steering wheel controls (like airbags or cruise control) will also be affected. This typically requires professional diagnosis and replacement.

Visually inspect the horn button for any signs of damage or sticking. Sometimes, debris can interfere with its operation.

Refer to your car's owner's manual for the exact location and identification of the horn relay.

Locate the horn relay in the fuse box. You can often test it by swapping it with an identical relay from a non-critical system or by using a multimeter to check for continuity and proper operation.

While checking the fuse, look for any signs of corrosion or damage in the fuse box terminals or surrounding wiring.

Locate the fuse box (usually under the dashboard or hood) and identify the horn fuse. Visually inspect it for a broken filament and replace it with a new one of the same amperage if blown.