2892400 - 5040BA Check operation of three-stage pressure switch

Wiring diagrams and pins
1-2, 2nd stage 3-4, 1st and 3rd stage

Check 1st stage (approx. 2.5 bar):

  • Disconnect the pressure switch from its pipe (see PROCEDURES OP.) and check that the circuit between pins 3 and 4 is open.
  • Reconnect the pressure switch to its pipe: the contact between pins 3 and 4 closes.
  • Reconnect the electrical connection of the pressure switch and switch on the system by pressing the A/C button on the air conditioner control panel.
  • Wait a few minutes. At the same time make sure that the compressor switches on normally.

The calibration of the 1st stage is:

  • contact opens 2.2 - 2.7 bar
  • contact closes 2.3 - 2.9 bar

Check 2nd stage (approx. 15 bar):

  • Operate the system with the car stopped.
  • Wait a few minutes: the contact between pins 1 and 2 closes. At the same time make sure that the fan comes on.

The calibration of the 2nd level is:

  • contact closes 14.2 - 16.2 bar;
  • contact opens 10.3 - 12.3 bar.

Check 3rd stage (approx. 28 bar):

  • It is advisable not to allow the pressure of the circuit to increase to that value, which is too close to the safety limits.
The calibration of this level cannot therefore be checked on the car.
However, if the system reached this value, the contact between pins 3 and 4 would open.

The calibration of the 3rd level is:

  • contact opens 25 - 30 bar;
  • contact closes 19 - 24 bar.