* The AC Compressor Clutch: This electromagnetic clutch engages the compressor, allowing it to spin and circulate refrigerant. If the clutch is faulty (worn, seized, or receiving no power), the compressor won't turn. This is a common failure point in AC systems.
Troubleshooting Steps:
1. Check the Clutch Relay: Locate the AC compressor relay (usually in the underhood fuse box). Swap it with a known good relay of the same amperage. If the compressor kicks on, you've found the problem.
2. Check the Clutch Circuit for Power: With the AC on, use a multimeter to test for power at the compressor clutch connector. You should have battery voltage when the AC is switched on. If no power is present, trace the wiring back to the relay, fuse, and AC control switch to identify the break in the circuit.
3. Check the Clutch Gap: If you have power at the connector and the relay is good, the problem could be a worn clutch. The gap between the clutch and the compressor pulley should be within specifications (check your repair manual for this). Too large a gap prevents engagement.
4. Inspect the Clutch for Damage: Carefully examine the clutch itself. Look for signs of damage like a burned-out coil, a seized pulley, or worn-out components.
5. Check the AC Cycling Switch: This is often located near the compressor. It can prevent the compressor from cycling on and off quickly.
6. Pressure Switch: A faulty low or high-pressure switch could prevent the compressor from turning on if the system pressure is outside the acceptable range.
Important Considerations:
* Safety First: Working with refrigerants requires proper handling and safety precautions. If you're not comfortable working with AC systems, take your vehicle to a qualified mechanic. Improper handling of refrigerant can be harmful to your health and the environment.
* Repair Manual: A repair manual specific to your 1999 Dodge Intrepid is highly recommended. It will show you the location of components, wiring diagrams, and specifications.
* Other Possibilities: While the clutch is the most likely culprit, other problems could prevent the compressor from engaging, such as a faulty AC control module, a bad compressor itself (though less common than a clutch issue), or low system pressure (despite your belief it's full — a leak somewhere may be causing this).
If you've checked the relay and have power to the clutch and it still isn't engaging, the clutch itself is likely the problem and needs replacing. However, always thoroughly troubleshoot the entire system before replacing parts.
