The air conditioning unit of the 1990 Honda Accord depends on a refrigerant called Freon. When the Freon is low, the air conditioning unit will begin to blow warmer air. In order to get the unit recharged and blowing cold air again, you must add Freon. "Recharging" is another word for the process, which isn't difficult. When you add Freon to the air conditioning unit at home, use this time for testing the system as well.
Check the AC pressure readings using an Air Conditioning gauge. The AC gauge set has colored hoses for connecting to the vehicle's compressor, which is on the side of the engine (left or right) and has two hoses connected to it. The AC gauge's blue hose fits on one hose (low side) fitting, and the red hose fits on the other hose (high side) fitting. The 1990 Honda Accord has screw-on fittings. Make the connections first, then start the engine and turn on the car's AC. Only add Freon if the AC pressure is low.
Alternatively, check the pressure when you connect the can of Freon to the vehicle.
Connect the hose on the can of Freon to the port on the larger of the two lines on the Accord's compressor. Turn on the Accord and run the air conditioning on the highest setting. Shake the Freon container vigorously. If the gauge is reading in the blue area, there is no need to add Freon. If it is in the green area, you need Freon.
Squeeze the trigger on the can of Freon when the compressor kicks on, to add Freon to the Accord's AC system. Release the trigger when the compressor kicks off and check the gauge on the can of Freon. Once the gauge reads in the blue area, you do not need to add any more Freon.
Turn the engine off and take the hose off the compressor's tubing. Check the operation of the Accord's air conditioning.
