This time of year, if the air conditioning isn’t working in your vehicle it can be very frustrating, not to mention uncomfortable.  No one likes to show up at a meeting or to see friends after sweating in your car for your entire drive.  If you consider yourself a weekend mechanic or a do-it-yourself kind of person, then this article is for you!  In this article, we’ll talk through some AC trouble shooting tips to help you diagnose the problem with your air conditioning.

The best place to start AC trouble shooting on your car is in the cabin of the vehicle.  Some AC problems can seem like a broken AC system when it’s really a problem with your ventilation system.  For example, a clogged cabin air filter can reduce airflow through your ventilation system leaving the air coming out of the vents feeling warm even if your AC system is working hard to keep things cool.  Another common ventilation system problem is that an air blend door isn’t functioning properly.  Behind your dash, there are a series of doors and flaps that divert air in your ventilation system over the cooling coils or heater core and to different ducting and vents.  In most newer cars, these doors are controlled by small servo motors.  Sometimes these motors can fail or the doors can become brittle and crack.  If this happens, the air may not be cooled even if the AC system is working well.  You can check these components by turning your key on but not starting your car and slowly changing from heat to cool and listen for the doors to move.  It’s very quiet but you can usually hear them moving if they’re functioning correctly.

Once you’ve checked the components in the cabin of your vehicle, it’s time to look under the hood.  The first thing to check is whether your compressor is engaging when the AC is switched on.  The engine belt on your engine is always turning the compressor pulley, but when you turn the AC on, the magnetic clutch will engage the pulley and allow the compressor to work.  You can check to see if this is happening by having a friend turn the AC on while you’re watching the compressor.  When then compressor engages, the center section of the pulley should start to spin as well.  If you don’t see the compressor engage when the air conditioning is turned on, you could have a few different problems.  First, it could be that you’ve got an electrical fault between the AC switch and the compressor.  Second, your compressor or the clutch could be broken, or third you there could be a conditioning in your air conditioning system that is keeping the compressor from engaging.

Your air conditioning system has a variety of temperature and pressure sensors to monitor what’s going on in the system.  There are certain conditions that will trip the compressor off to keep things safe like an abnormally high pressure or high temperature, or even a low pressure.  If your compressor isn’t coming on you need to do a little more AC trouble shooting to figure out what’s going on.

It’s possible that one of the sensors has gone bad in the system giving a false indication and causing your compressor not to turn on for no good reason so you can start by testing the pressure and temperature sensors in the system.  Since every vehicle is different, you’ll probably need a repair manual specific to your car for this step.  If you’re confident you’ve got good sensors the last thing to do is check the system pressures to see if they really are too low or too high.  You will need a set of mechanic’s AC gauges to check pressures in your system and can find those at most local auto parts stores.  Using these gauges, you can check the pressures in your system and finish your AC trouble shooting.  If you find a high pressure, the cause is often a clog usually in the expansion valve or dryer.  If you find a low pressure, the problem is usually due to a leak in your system and a low refrigerant level.

If you find a leak in your system use Red Angel A/C Stop Leak to seal the leak and get your air conditioning system back to normal.

You can purchase Red Angel A/C Stop Leak at any of our partnering local auto parts stores like:

• AutoZone
• Advance Auto Parts
• Bennett Auto Supply
• CarQuest Auto parts
• NAPA Auto Parts
• O’Reilly Auto Parts
• Pep Boys
• Fast Track
• Bumper to Bumper Auto Parts Specialists
• S&E Quick Lube Distributer
• DYK Automotive
• Fisher Auto Parts stores
• Auto Plus Auto Parts stores
• Hovis Auto & Truck Supply stores
• Salvo Auto Parts
• Advantage Auto Stores
• Genuine Auto Parts stores
• Bond Auto Parts stores
• Tidewater Fleet Supply
• Bumper to Bumper Auto Parts
• Any Part Auto Parts
• Consumer Auto Parts

 

Pictures Provided By:

ac_trouble_shooting.jpg – By Rusak – Licensed by Getty Images – Original Link
cabin_air_filter.jpg – By Norasit Kaewsai – Licensed by Getty Images – Original Link