How to Troubleshoot A/C Problems in an Automobile Car

Air conditioning has become commonplace in many automobiles. Modern air conditioning systems use a refrigerant and a pump to cool the passenger cabin. When this system fails, you won't get any cold air in the cabin. However, there are a few things that could be wrong with the system; troubleshooting the problem before having it fixed could help save you from an expensive repair bill.

Things You'll Need

  • A/C pressure gauge
  • Turn the engine on and turn the fan speed to "high."

  • Turn the A/C on and check for cold air. If there is no cold air, leave the A/C on and the engine running.

  • Open the hood and inspect the air conditioning pump for leaks. Locate the low pressure A/C line on your vehicle's A/C system. This will be a hard steel line with a blue cap on the line covering a valve. Remove the blue cap and connect the A/C pressure gauge to the low pressure A/C line using the quick-connect fitting on the pressure gauge. Check the pressure on the gauge. If it falls outside of the "green bar" on the gauge, the pressure is too low, which means there is a leak in the A/C system. Leaks usually happen at the pump, but there could be a physical hole in one of the A/C lines.

  • Inspect the A/C lines for physical damage. Run your hand along the steel piping. If you don't find any holes or feel any leaks (they will be noticeable), then the problem is with the A/C pump. You'll need to have the pump replaced.