Tools you'll likely need:
* Socket wrench set (metric)
* Ratchet
* Extensions
* Possibly a deep well socket depending on access
* Wire connectors or crimpers (depending on how you disconnect the wires)
* Rags or shop towels
* Safety glasses
* Possibly a pressure gauge (for testing the switch after replacement)
Steps:
1. Safety First: Disconnect the negative battery cable. This prevents accidental shorts and electrical shocks.
2. Locate the Pressure Cycling Switch: The pressure cycling switch is typically located on the compressor or near the accumulator/dryer on the A/C system's low-pressure side. Consult your repair manual for the precise location on your specific Blazer model. It's usually a small electrical switch with one or more wires attached.
3. Recover Refrigerant (Crucial): Before disconnecting anything, you MUST have the refrigerant recovered from the A/C system by a qualified technician. Discharging refrigerant into the atmosphere is illegal and harmful to the environment. Skipping this step will damage the A/C system and expose you to harmful chemicals.
4. Disconnect the Electrical Connector(s): Carefully disconnect the electrical connector(s) from the pressure cycling switch. Take note of how they're connected so you can reattach them correctly. You may need to gently pry the connector open or use a small flathead screwdriver to release it.
5. Disconnect the Vacuum Line (If Applicable): Some models may have a small vacuum line connected to the switch. If present, carefully disconnect it.
6. Remove the Switch: Use the appropriate socket to remove the pressure cycling switch from its mounting location. It may be held in place by a nut or bolt.
7. Install the New Switch: Install the new pressure cycling switch in the same location, ensuring it's securely fastened.
8. Reconnect Everything: Reconnect the electrical connector(s) and vacuum line (if applicable).
9. Reconnect the Battery: Reconnect the negative battery cable.
10. Recharge the A/C System: You MUST have a qualified technician recharge the A/C system with the correct amount of refrigerant. Improper charging can damage the compressor.
Important Considerations:
* Refrigerant: Handling refrigerant requires special equipment and training. Do not attempt to work on the A/C system without proper knowledge and equipment.
* Pressure: The A/C system operates under pressure. Be careful not to damage any components.
* Repair Manual: Refer to your Blazer's repair manual for specific details and diagrams related to your vehicle's A/C system. The location and type of switch can vary.
* Testing: After installation, a qualified technician should test the system to ensure proper operation.
This is general guidance. Improperly working on your A/C system can lead to damage and injury. If you're not comfortable performing this repair, it's best to take your Blazer to a qualified mechanic. The cost of professional service is far less than the potential cost of damaging your A/C system.
