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 appropriate SELF-DIAGNOSTICS article in ENGINE PERFORMANCE.
- 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 36.5°F (2.5°C) | Off | ||
| Greater Than 39.2°F (4°C) | On | ||