Diagnostic Aids
WARNING: This page is about a different car, the 2003 Oldsmobile Bravada, 2003 GMC Envoy XL, 2003 GMC Envoy, and 2003 Chevrolet TrailBlazer. However, it is still accessible from the selected car via links, so may be relevant.
- The A/C compressor is protected from overheating by the compressor temperature switch, which is mounted at the rear of the A/C compressor. The switch is wired internally to the compressor and is not serviceable. The switch opens and disengages the compressor clutch when temperatures reach 135°F (275°F). The switch closes when the compressor temperature cools to 120°C (248° F).
- A/C compressor clutch will not engage under the following conditions:
- The A/C high side line pressure is over 2413 kPa (350 psi).
- The A/C low side line pressure is under 151 kPa (22 psi).
- Throttle angle is at 100 percent.
- Engine speed is more than 5500 RPM.
- Engine coolant temperature (ECT) is more than 123°C (253°F).
- Ambient air temperature is less than 1°C (35°F).