1. Install a pressure gauge to the highway.
2. Start the engine, leave to work on engine speed 2000 min -1 and set the maximum cooling at high fan speed.
3. Open the windows or doors.
4. Set the dry bulb air intake grille in the vehicle.
5. Install the wet and dry thermometer as close as possible to the inlet of the cooling unit.
6. Verify that the pressure indicated by the pressure gauge is in the range 1,373-1,575 psi. If the pressure is too high, add water to the condenser. If the pressure is too low, close the front side of the condenser.
7. Check that the temperature of the air in the air intake grille in the interior of the vehicle is in the range 25-35 ?° C.
8. According to the schedule, calculate the relative humidity by comparing the temperature of the wet and dry thermometers.
9. Measure the temperature of the air intake grille in the interior of the vehicle and calculate the difference between the dry bulb and a thermometer in the air intake grille.
10. Verify that if the intersection of relative humidity and temperature differences are within the tolerance, then the air conditioning system is operating properly.