2. With the engine running, set the A/C control to a low temperature and turn on the fan to a high speed.
3. Ask an assistant to press the air conditioner on button, while you watch the compressors yourself. The clutch should make an audible click and the compressor should begin to rotate. If the compressor does not start, stop the engine and disconnect the A/C pressure sensor. Close the jumper terminals of the sensor connector and try to turn on the air conditioner again (see fig. 14.12). If the compressor is now running, the pressure in the system is either too high or too low. Let your system be tested by a specialist.
Note. On the 1993-1995 Mazda modems, the reptiles pressure sensor of the air conditioning system is located in the refrigerant pipeline going to the dryer receiver (not on the receiver). This pipeline with the sensor is located between the front bumper and the radiator.
4. If the clutch does not turn on, check the clutch connector to see if battery voltage is applied to the clutch when the air conditioner is turned on. If voltage is applied to the clutch connector, turn off the ignition and disconnect the compressor electrical connector. Connect positive voltage from the battery with a jumper wire directly to the clutch connector pin. If the clutch does not turn on now, then it is faulty and must be replaced.
5. If there is no voltage at the clutch connector, check the integrity of the corresponding fuses in the passenger compartment and under the hood. If the fuses are open, remove the A/C relay from the fuse/relay box under the hood. Check the relay as indicated in chapter 12.
6. After removing the relay, turn on the ignition and check for battery voltage at terminals 3 and 5 of the A/C relay in the fuse/relay box (pic. 15.6). There should be voltage on both pins. Close pins 2 and 3 with a jumper and listen to see if the clutch engages.
7. If the clutch still does not engage and the relay, fuses, and clutch itself are OK, check for an open circuit between the relay box and the clutch connector. If the circuit is OK, check the integrity of the circuit between the ECU and the relay box. If this circuit does not have a break, send the BEU for verification.