Testers for Air Conditioning Pressure Switches

Pressure switches monitor defined pressure ranges within automotive air conditioning systems. A faulty switch can prevent the air conditioning compressor from engaging, cause the system to shut down unexpectedly, or result in erratic switching behavior.

Using appropriate pressure and vacuum pumps, air conditioning pressure switches can be tested either inside or outside the designated test setup. This process verifies the pressure at which the electrical switching occurs and whether the measured values comply with the manufacturer’s specifications.

Testing Low-, Medium-, and High-Pressure Switches

Depending on their function, air conditioning pressure switches monitor different pressure ranges. Therefore, different test devices are required for their testing.

For low-pressure switches, a test device capable of precisely generating and measuring both negative pressure and slight overpressure is suitable.

Medium- and high-pressure switches, on the other hand, require a pressure pump capable of generating correspondingly higher test pressures.

During testing, the following values, among others, can be determined:

• Activation point
• Deactivation point
• Switching point
• Switching differential or hysteresis

The pressure is controlled and varied, and at the same time, the moment when the pressure switch’s electrical contact changes its state is observed.

Leitenberger Autotest Devices offers a variety of hand pumps for low-, medium-, and high-pressure ranges. Compatible connection adapters allow for connection to various pressure switches.

The required test range as well as the setpoints for make and break points depend on the specific pressure switch and the specifications of the vehicle or component manufacturer.