Air Condition Cycling On And Off

[Roker 4]

I purchased one of those kits from Halfords to re-charge my air conditioning system. When I connected it to the LP side and turned the AC full on, the gauge was cycling between 10 psi and 40 psi every 5 seconds approx. To be safe I did not put any refrigerant in to the system for fear of overcharging it.

I notice previously it was blowing hot and cold.

Outside temperature 10°C.

Last charged by an AC specialist 3 year ago

Is this normal with a cool outside air temperature/ Any ideas please?

[Fitter 3]

The correct way to check the air conditioning is to have the vehicle in an ambient temperature of 18C (65F) and set the temperature in the car to minimum. Allow the air con to run for about five minutes and check the pressure at the LP port. The condition you describe is usual with low refrigerant. When there is too much R134 in the system the guage will go into the red section.

Fitter

[Roker 4]

Thanks. I was concerned that the pressure when it was high (40psi) was reading way over the recommended for the outside temperature, which made me reluctant to add any refrigerant.