The Blazer A/C system is filled with R-134A refrigerant, which is not commercially available for recharging the system. You will have to have the system drained and filled by a professional before and after performing repairs. The evaporator core cools air before it enters the passenger compartment.
Take your vehicle to an air conditioning professional and have them drain the refrigerant. Do not attempt any A/C repairs without draining refrigerant.
Loosen and remove the negative battery cable with a socket or box wrench. Place a plastic container under the radiator drain and open the drain cock with your fingers or pliers. Empty the coolant level to below the level of the heater core.
Pull the blower resistor from the evaporator case. Pull apart the wiring harnesses and connectors from the blower motor. Pull off the inlet tube to the evaporator. Block off all tube and hose openings with cloths or plastic to prevent dirt or contaminants getting inside them.
Remove the compressor hose and accumulator (not all models have them) and block off all openings. Loosen and remove the screws holding the evaporator case together using a screwdriver. Pre-1994 models must have their accumulator inlet hoses removed and openings blocked. Loosen and remove the screws holding the blower motor case to the evaporator case with a screwdriver. Remove the evaporator core.
