Why Isn’t My Car’s Air Conditioning Working?

by Suzanne Carroll
auto repair shop

On a hot summer day, a car’s interior temperature can get dangerously hot. That’s why it’s important to make sure your car has a functioning air conditioning system. If you’ve noticed that the A/C isn’t running as well as it used to (or has stopped running entirely), there could be several reasons for the problem. Sometimes, A/C repair is an easy fix you can do yourself, but other causes require a trip to the mechanic. Here are some tips to help you solve your car’s air conditioning issues:

  • Look for obstructions. If any debris (leaves, insects, etc.) gets lodged under the hood or in the grill, it could impact the air conditioning system’s ability to run efficiently. Remove any obstructions and see if this fixes the problem.
  • Check the cabin air filter. A clogged cabin filter will force your air conditioner to work harder than it should, which puts pressure on the system and makes it less efficient. Cabin filters should be replaced every three years or so.
  • Locate the leak. Auto repair professionals report that most A/C problems are caused by leaking refrigerant. A leak can occur anywhere in the system; your mechanic will check the appropriate hoses, valves and fittings to determine the origin of the leak.
  • Test the compressor. When your car’s air conditioner is running, the compressor clutch will spin regularly. If it stops and starts, that could be a sign of low refrigerant and a potential leak somewhere in the system.
  • Is the cooling fan working? If your car’s A/C system is emitting lukewarm air, it could be a sign of a broken cooling fan. An auto repair service can diagnose the problem and replace the fan if necessary.
  • Is the condenser working? Warm air could also be a sign of issues with the condenser, which cools and distributes refrigerant. The condenser may just need to be thoroughly cleaned, but if it has been physically damaged, it’ll need to be replaced.


If you need help with your car’s air conditioning, the Diamond Certified Resource has identified highly qualified, top rated auto repair shops throughout the Bay Area.