A 1992 Chevy S10 Blazer likely used
R-12 (Freon-12). However,
it's crucial to understand that R-12 is no longer manufactured due to its harmful effects on the ozone layer. Any repair shop working on your AC system should be using an approved R-12 substitute, such as
R-134a (after converting the system appropriately), or a blend designed for R-12 systems.
Do not attempt to add R-12 yourself. It's illegal in most places to handle or purchase it. Instead, take your Blazer to a qualified automotive air conditioning technician for diagnosis and repair. They will be able to determine the correct refrigerant and ensure the system is properly serviced.
