Common signs of a faulty or malfunctioning low-pressure switch may include AC systems that cut off and on rapidly, an inability to effectively cool an interior environment as well as compressors that do not switch on. The low-pressure switch shuts down the system when pressure drops past a certain point. Malfunctioning switches may place other mechanical components at greater risk of suffering damage.
While air conditioning systems typically cycle on and off in order to maintain the right temperature, those that suffer from a faulty low-pressure switch may cycle on and off rapidly. Systems that seize up or freeze beginning at the evaporator coils may also indicate a malfunctioning low-pressure switch. Always inspect and test the switch in the event that the compressor fails to engage. Complete failure of the low-pressure switch can lead to other mechanical issues as well as the loss of refrigerant from within the system.
Other mechanical issues that may interfere with the operation of the low-pressure switch may include a refrigerant leak or failure of the blower motor. Plugged evaporator coils or blocked air flow may also interfere with the function of the low-pressure switch. Proper operation of all pressure switches is essential for protecting the system from damage and catastrophic failure.