A/C Amplifier
- Turn A/C on. Ensure A/C amplifier control functions are as follows: idle speed is increased by Idle Air Control (IAC) valve. A/C compressor clutch engagement is delayed briefly after IAC valve comes on and A/C on signal is transmitted to Engine Control Module (ECM). If idle and compressor operation are not as specified, see BASIC TESTING article in the ENGINE PERFORMANCE section.
- The A/C system operation should be as indicated in A/C AMPLIFIER TESTING table. The A/C system should be off while cranking engine. The A/C system should come on within 3.5 seconds of full throttle opening (80 percent open).
A/C AMPLIFIER TESTING
| Condition | A/C System Operation | |
|---|---|---|
| Refrigerant Pressures | ||
| High Side | ||
| Greater Than 455 psi (32.0 kg/cm2 ) | Off | |
| Less Than 370 psi (26.0 kg/cm2 ) | On | |
| Low Side | ||
| Less Than 28.4 psi (2.0 kg/cm2 ) | Off | |
| Greater Than 32.7 psi (2.3 kg/cm2 ) | On | |
| Engine Coolant Temperature | ||
| Greater Than 230°F (110°C) | Off | |
| Less Than 217°F (103°C) | On | |
| Evaporator Temperature | ||
| Less Than 34°F (1°C) | Off | |
| Greater Than 35°F (2°C) | On | |